Feedback device and method for providing thermal feedback by means of same

ABSTRACT

The present invention relates to a feedback device and a thermal feedback provision method using the same. The thermal feedback provision method may include checking first operating power applied to a first thermoelectric couple group for a first thermoelectric operation and second operating power applied to a second thermoelectric couple group for a second thermoelectric operation when the first thermoelectric operation is initiated in the first thermoelectric couple group to initiate the output of the first thermal feedback after the second thermoelectric operation is initiated in the second thermoelectric couple group to initiate the output of the second thermal feedback and include applying cognitive enhancement power for enhancing a user&#39;s cognition to the first thermoelectric couple group from a time point at which the output of the first thermal feedback is initiated up to a first time point so that the user&#39;s cognition of the first thermal feedback is enhanced.

TECHNICAL FIELD

The present invention relates to a feedback device configured to outputa thermal feedback and a thermal feedback providing method using thesame.

BACKGROUND ART

Recently, with the development of technologies for virtual reality (VR)and augmented reality (AR), demands for providing feedback throughvarious senses to improve user's immersion in content have beenincreasing. In particular, in the 2016 Consumer Electronics Show (CES),virtual reality technology was introduced as one of future promisingtechnologies. With this trend, research is being actively carried out toprovide a user experience with respect to all human senses including anolfactory sense and a tactile sense beyond a user experience (UX) whichis mainly limited to a visual sense and an auditory sense.

A thermoelement (TE) is a device which produces an exothermic reactionor an endothermic reaction through a Peltier effect by receivingelectric energy. The thermoelement is expected to be used for providingthermal feedback to a user. However, a conventional thermoelement mainlyusing a flat substrate has been limited in application thereof becauseit is difficult to press the conventional thermoelement against a user'sbody part.

However, in recent years, as development of a flexible thermoelement(FTE) has reached a successful stage, the flexible thermoelement isexpected to overcome the problems of the conventional thermoelectricdevices and to effectively transfer thermal feedback to a user.

DETAILED DESCRIPTION OF THE INVENTION Technical Problem

The present invention is directed to providing a feedback deviceconfigured to provide a thermal feedback to a user and a thermalfeedback providing method using the same.

The present invention is also directed to providing a thermal feedbackproviding method capable of improving a user's cognition of a thermalfeedback.

The present invention is also directed to providing a thermal feedbackproviding method capable of reducing a sensing time of a user withrespect to a thermal feedback.

The present invention is also directed to providing a thermal feedbackproviding method capable of reducing an output end time of a thermalfeedback.

The present invention is also directed to providing a feedback devicecapable of improving waste heat dissipation performance and coldsensation provision performance.

The technical problem of the present invention is not limited to theaforementioned problems, and other problems which are not mentioned herecan be clearly understood by those skilled in the art from the followingdescription and the accompanying drawings.

Technical Solution

According to an aspect of the present invention, a method for providinga thermal feedback performed by a feedback device outputting the thermalfeedback by transferring heat generated by a thermoelectric operationincluding at least one of an exothermic operation and an endothermicoperation of a thermoelectric element to which power is applied to auser through a contact surface which contacts with the user's body part,wherein the thermoelectric element is provided by a thermoelectriccouple array including a first thermoelectric couple group and a secondthermoelectric couple group which are individually controllable, andwherein the contact surface includes a first contact surfacecorresponding to the first thermoelectric couple group and a secondcontact surface corresponding to the second thermoelectric couple groupmay comprise: when a first thermoelectric operation is initiated at thefirst thermoelectric couple group and an output of a first thermalfeedback is initiated after a second thermoelectric operation isinitiated at the second thermoelectric couple group and an output of asecond thermal feedback is initiated, checking a first operating powerapplied to the first thermoelectric couple group for the firstthermoelectric operation and a second operating power applied to thesecond thermoelectric couple group for the second thermoelectricoperation, the first operating power being determined according to atype and an intensity of the first thermal feedback, the secondoperating power being determined according to a type and an intensity ofthe second thermal feedback; and applying a cognitive enhancing power tothe first thermoelectric couple group for the user's cognitiveenhancement from an output start time point of the first thermalfeedback to a first time point so that the user's cognition to the firstthermal feedback is enhanced.

Technical solutions of the present invention are not limited to theaforementioned solutions, and other solutions which are not mentionedhere can be clearly understood by those skilled in the art from thefollowing description and the accompanying drawings.

Advantageous Effects of the Invention

According to the present invention, it is possible to provide a thermalfeedback to a user.

According to the present invention, it is also possible to improve auser's cognition of a thermal feedback.

According to the present invention, it is also possible to reduce asensing time of a user with respect to a thermal feedback.

According to the present invention, it is also possible to reduce anoutput end time of a thermal feedback.

Advantageous effects of the invention are not limited to theaforementioned effects, and other advantageous effects which are notmentioned here will be clearly understood by those skilled in the artfrom the following description and the accompanying drawings.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing a configuration of a thermalexperience providing system 1000 according to an embodiment of thepresent invention.

FIG. 2 is a block diagram showing a content reproduction device 1200according to an embodiment of the present invention.

FIG. 3 is a block diagram showing a configuration of an audiovisualdevice 1400 according to an embodiment of the present invention.

FIG. 4 is a block diagram showing a configuration of a feedback device1600 according to an embodiment of the present invention.

FIG. 5 is a block diagram showing a configuration of a heat outputmodule 1640 according to an embodiment of the present invention.

FIG. 6 is a diagram showing an aspect of the heat output module 1640according to an embodiment of the present invention.

FIG. 7 is a diagram showing another aspect of the heat output module1640 according to an embodiment of the present invention.

FIG. 8 is a diagram showing still another aspect of the heat outputmodule 1640 according to an embodiment of the present invention.

FIG. 9 is a diagram showing yet another aspect of the heat output module1640 according to an embodiment of the present invention.

FIG. 10 is a diagram showing an exothermic operation for providing a hotfeedback according to an embodiment of the present invention.

FIG. 11 is a graph showing the intensity of a hot feedback according toan embodiment of the present invention.

FIG. 12 is a diagram showing an endothermic operation for providing acold feedback according to an embodiment of the present invention.

FIG. 13 is a graph showing the intensity of a cold feedback according toan embodiment of the present invention.

FIG. 14 is a graph showing the intensity of a hot/cold feedback usingvoltage adjustment according to an embodiment of the present invention.

FIG. 15 is a graph showing adjustment of the intensity of a hot/coldfeedback through operation control for each thermoelectric couple group1644 according to an embodiment of the present invention.

FIG. 16 is a graph showing adjustment of the intensity of a hot/coldfeedback through power application timing control according to anembodiment of the present invention.

FIG. 17 is a diagram showing a voltage adjustment-based thermal grilloperation according to an embodiment of the present invention.

FIG. 18 is a table regarding a voltage for providing a neutral thermalgrill feedback through voltage adjustment according to an embodiment ofthe present invention.

FIG. 19 is a schematic diagram showing an example electric signal for aheat transfer operation according to an embodiment of the presentinvention.

FIG. 20 is a diagram showing the heat transfer operation of FIG. 19according to an embodiment of the present invention.

FIG. 21 is a schematic diagram showing another example electric signalfor the heat transfer operation according to an embodiment of thepresent invention.

FIG. 22 is a diagram showing the heat transfer operation of FIG. 21according to an embodiment of the present invention.

FIG. 23 is a schematic diagram showing yet another example electricsignal for the heat transfer operation according to an embodiment of thepresent invention.

FIG. 24 is a diagram showing a heat transfer operation according to anembodiment of the present invention.

FIG. 25 is a schematic diagram showing yet another example electricsignal for the heat transfer operation according to an embodiment of thepresent invention.

FIG. 26 is a diagram showing the heat transfer operation of FIG. 25according to an embodiment of the present invention.

FIG. 27 is a diagram illustrating a change in applied voltage forgenerating an overshoot of a thermal feedback and a change intemperature with respect to the overshoot according to an embodiment ofthe present invention.

FIG. 28 is a diagram illustrating a change in applied voltage forgenerating an overshoot of a thermal feedback and a change intemperature with respect to the overshoot according to anotherembodiment of the present invention.

FIG. 29 is a diagram illustrating a change in applied voltage forgenerating an overshoot of a thermal feedback and a change intemperature with respect to the overshoot according to still anotherembodiment of the present invention.

FIG. 30 is a diagram illustrating a change in applied voltage forgenerating an overshoot of a cold feedback and a change in temperaturewith respect to the overshoot according to an embodiment of the presentinvention.

FIG. 31 is a flowchart showing a thermal feedback recognitionenhancement method according to an embodiment of the present invention.

FIG. 32 is a diagram showing a change in temperature on a contactsurface and a change in applied voltage according to a thermal feedbackrecognition enhancement method when thermal feedbacks with the sameintensity are output from a first thermoelectric couple group and asecond thermoelectric couple group according to an embodiment of thepresent invention.

FIG. 33 is a diagram showing a change in temperature on a contactsurface and a change in applied voltage according to a thermal feedbackrecognition enhancement method when thermal feedbacks with the sameintensity are output from the first thermoelectric couple group and thesecond thermoelectric couple group according to another embodiment ofthe present invention.

FIGS. 34A and 34B are diagrams showing a change in temperature on acontact surface according to a thermal feedback recognition enhancementmethod when a thermal feedback with a higher intensity is output fromthe second thermoelectric couple group than from the firstthermoelectric couple group according to an embodiment of the presentinvention.

FIGS. 35A-35C are diagrams showing a change in temperature on a contactsurface according to a thermal feedback recognition enhancement methodwhen a thermal feedback with a lower intensity is output from the secondthermoelectric couple group than from the first thermoelectric couplegroup according to an embodiment of the present invention.

FIGS. 36A and 36B are diagrams showing a change in temperature on acontact surface according to a thermal feedback recognition enhancementmethod when a hot feedback is output from the first thermoelectriccouple group and a cold feedback is output from the secondthermoelectric couple group according to an embodiment of the presentinvention.

FIGS. 37A and 37B are diagrams showing a change in temperature on acontact surface according to a thermal feedback recognition enhancementmethod when a cold feedback is output from the first thermoelectriccouple group and a hot feedback is output from the second thermoelectriccouple group according to an embodiment of the present invention.

FIG. 38 is a diagram showing a change in temperature on a contactsurface and a change in applied voltage according to a thermal feedbackrecognition enhancement method when a cold feedback is output from thefirst thermoelectric couple group and the second thermoelectric couplegroup according to an embodiment of the present invention.

FIGS. 39 to 41 are diagrams showing a change in temperature on a contactsurface according to a voltage application time point in the firstthermoelectric couple group and the second thermoelectric couple groupin the thermal feedback recognition enhancement method according to anembodiment of the present invention.

FIG. 42 is a flowchart showing a method of reducing a response time of athermal feedback according to an embodiment of the present invention.

FIG. 43 is a diagram showing a change in temperature on a contactsurface and a change in applied voltage according to the method ofreducing a response time of a thermal feedback when a hot feedback isoutput from a thermoelectric couple group according to an embodiment ofthe present invention.

FIG. 44 is a diagram showing a change in temperature on a contactsurface and a change in applied voltage according to the method ofreducing a response time of a thermal feedback when a hot feedback isoutput from a thermoelectric couple group according to anotherembodiment of the present invention.

FIG. 45 is a diagram showing a change in temperature on a contactsurface and a change in applied voltage according to the method ofreducing a response time of a thermal feedback when a hot feedback isoutput from a thermoelectric couple group according to still anotherembodiment of the present invention.

FIG. 46 is a diagram showing a change in temperature on a contactsurface and a change in applied voltage according to the method ofreducing a response time of a thermal feedback when a cold feedback isoutput from a thermoelectric couple group according to an embodiment ofthe present invention.

FIG. 47 is a diagram showing a change in temperature on a contactsurface and a change in applied voltage according to a method ofreducing a response time of a thermal feedback when a thermal grillfeedback is output from a thermoelectric couple group according to anembodiment of the present invention.

FIGS. 48A and 48B are diagrams showing a thermal feedback outputoperation according to an embodiment of the present invention.

FIG. 49 is a flowchart showing a thermal experience providing methodconsidering a reduced response time according to an embodiment of thepresent invention.

FIGS. 50A and 50B are diagrams showing a thermal feedback outputoperation of a thermal experience providing method considering a reducedresponse time according to an embodiment of the present invention.

FIG. 51 is a flowchart showing a thermal experience providing methodconsidering a reduced response time according to another embodiment ofthe present invention.

FIG. 52 is a flowchart showing an end time reduction method for athermal feedback according to an embodiment of the present invention.

FIG. 53 is a diagram showing a change in temperature on a contactsurface and a change in applied voltage according to the end timereduction method for the thermal feedback when a hot feedback is outputfrom a thermoelectric couple group according to an embodiment of thepresent invention.

FIG. 54 is a diagram showing a change in temperature on a contactsurface and a change in applied voltage according to the end timereduction method for the thermal feedback when a hot feedback is outputfrom a thermoelectric couple group according to another embodiment ofthe present invention.

FIG. 55 is a diagram showing a change in temperature on a contactsurface and a change in applied voltage according to the end timereduction method for the thermal feedback when a hot feedback is outputfrom a thermoelectric couple group according to still another embodimentof the present invention.

FIG. 56 is a diagram showing a change in temperature on a contactsurface and a change in applied voltage according to the end timereduction method for the thermal feedback when a cold feedback is outputfrom a thermoelectric couple group according to an embodiment of thepresent invention.

FIG. 57 is a diagram showing a change in temperature on a contactsurface and a change in applied voltage according to the end timereduction method for the thermal feedback when a thermal grill feedbackis output from a thermoelectric couple group according to an embodimentof the present invention.

FIGS. 58A and 58B are diagrams showing a change in temperature on acontact surface and a change in applied voltage when a hot feedback iscontinuously output from a thermoelectric couple group according to anembodiment of the present invention.

FIG. 59 is a block diagram showing a configuration of the feedbackdevice 1600 according to another embodiment of the present invention.

FIG. 60 is a diagram showing a configuration of the feedback device 1600according to an embodiment of the present invention.

FIG. 61 is a diagram showing a structure of the feedback device 1600 towhich a heat buffer material is applied according to an embodiment ofthe present invention.

BEST MODE

To solve the above technical problems, according to an embodiment of thepresent invention, there is provided a method for providing a thermalfeedback performed by a feedback device outputting the thermal feedbackby transferring heat generated by a thermoelectric operation includingat least one of an exothermic operation and an endothermic operation ofa thermoelectric element to which power is applied to a user through acontact surface which contacts with the user's body part, wherein thethermoelectric element is provided by a thermoelectric couple arrayincluding a first thermoelectric couple group and a secondthermoelectric couple group which are individually controllable, andwherein the contact surface includes a first contact surfacecorresponding to the first thermoelectric couple group and a secondcontact surface corresponding to the second thermoelectric couple groupmay comprise: when a first thermoelectric operation is initiated at thefirst thermoelectric couple group and an output of a first thermalfeedback is initiated after a second thermoelectric operation isinitiated at the second thermoelectric couple group and an output of asecond thermal feedback is initiated, checking a first operating powerapplied to the first thermoelectric couple group for the firstthermoelectric operation and a second operating power applied to thesecond thermoelectric couple group for the second thermoelectricoperation, the first operating power being determined according to atype and an intensity of the first thermal feedback, the secondoperating power being determined according to a type and an intensity ofthe second thermal feedback; and applying a cognitive enhancing power tothe first thermoelectric couple group for the user's cognitiveenhancement from an output start time point of the first thermalfeedback to a first time point so that the user's cognition to the firstthermal feedback is enhanced.

MODE OF THE INVENTION

Hereinafter, embodiments will be described in detail with reference tothe accompanying drawings. However, the present invention is notrestricted or limited to the embodiments. Like reference numerals in thedrawings denote like elements.

According to an aspect of the present invention, a method for providinga thermal feedback performed by a feedback device outputting the thermalfeedback by transferring heat generated by a thermoelectric operationincluding at least one of an exothermic operation and an endothermicoperation of a thermoelectric element to which power is applied to auser through a contact surface which contacts with the user's body part,wherein the thermoelectric element is provided by a thermoelectriccouple array including a first thermoelectric couple group and a secondthermoelectric couple group which are individually controllable, andwherein the contact surface includes a first contact surfacecorresponding to the first thermoelectric couple group and a secondcontact surface corresponding to the second thermoelectric couple groupmay comprise: when a first thermoelectric operation is initiated at thefirst thermoelectric couple group and an output of a first thermalfeedback is initiated after a second thermoelectric operation isinitiated at the second thermoelectric couple group and an output of asecond thermal feedback is initiated, checking a first operating powerapplied to the first thermoelectric couple group for the firstthermoelectric operation and a second operating power applied to thesecond thermoelectric couple group for the second thermoelectricoperation, the first operating power being determined according to atype and an intensity of the first thermal feedback, the secondoperating power being determined according to a type and an intensity ofthe second thermal feedback; and applying a cognitive enhancing power tothe first thermoelectric couple group for the user's cognitiveenhancement from an output start time point of the first thermalfeedback to a first time point so that the user's cognition to the firstthermal feedback is enhanced.

Herein, the cognitive enhancing power may include a first excess powergenerating a first excess time interval in which a temperature of thefirst contact surface exceeds a first target temperature according to atype and an intensity of the first thermal feedback, and the applyingthe cognitive enhancing power may be applying the first excess powerfrom an output start time point of the first thermal feedback to thefirst time point.

Herein, the method for providing a thermal feedback according an aspectof the present invention may further comprise applying the firstoperating power to the first thermoelectric couple group such that atemperature of the first contact surface reaches to the first targettemperature at the elapse of the first time point.

Herein, the first excess power may be a power in the same direction asthe first operating power.

Herein, the first excess power may be in the same direction as the firstoperating power, and a voltage level of the first excess power isgreater than a voltage level of the first operating power.

Herein, the applying the cognitive enhancing power may be applying thefirst excess power in the form of a duty signal.

Herein, when performing the applying the cognitive enhancing power, whena 1-1 excess power having a first voltage level is applied to the firstthermoelectric couple group, a temperature of the first contact surfacemay exceed the first target temperature faster than applying a 1-2excess power having a second voltage level to the first thermoelectriccouple group, wherein the second voltage level is less than the firstvoltage level.

Herein, when performing the applying the cognitive enhancing power, whenthe first excess power is applied from an output start time point of thefirst thermal feedback to the first time point, a temperature varianceof the first contact surface may be larger than a temperature varianceof applying the first excess power from the output start time point ofthe first thermal feedback to a predetermined time point, wherein thepredetermined time point is a time point before the first time point.

Herein, when performing the applying the cognitive enhancing power, whenan intensity of the first thermal feedback is a first intensity, and thefirst target temperature is a 1-1 target temperature corresponding tothe first intensity, the first excess power may be applied so that atemperature of the first contact surface does not reach a 1-2 targettemperature corresponding to a second intensity higher than the firstintensity in the first excess time interval.

Herein, when performing the applying the cognitive enhancing power, thefirst time point for applying the first excess power may be determinedsuch that an application of the first excess power is stopped after atemperature of the first contact surface exceeds the first targettemperature by applying the first excess power.

Herein, the applying the cognitive enhancing power may be applying thefirst excess power such that a temperature variance of the first contactsurface during a time interval from an output start time point of thefirst thermal feedback to the first time point that the first excesspower is applied is greater than a temperature variance of the firstcontact surface during the time interval that the first operating power.

Herein, a second excess power generating a second excess time intervalin which a temperature of the second contact surface exceeds a secondtarget temperature according to a type and an intensity of the secondthermal feedback may be applied to the second thermoelectric couplegroup from an output start time point of the first thermal feedback to asecond time point so that the user's cognition to the second thermalfeedback is enhanced.

Herein, the applying the cognitive enhancing power may be determining anoutput start time point of the first thermal feedback to be any one of atime point between an output start time point of the second thermalfeedback and the second time point so that the first excess timeinterval overlaps at least a portion of the second excess time interval.

Herein, the applying the cognitive enhancing power may be determining anoutput start time point of the first thermal feedback to the second timepoint so that a temperature change of the first contact surface startswhen a temperature change direction of the second contact surfacechanges.

Herein, the applying the cognitive enhancing power may be determining anoutput start time point of the first thermal feedback to a time pointafter the second time point so that the first excess time interval doesnot overlap the second excess time interval.

Herein, when performing the recognizing the cognitive enhancing power,the cognitive enhancing power may include the first operating power, andwhen an intensity of the first thermal feedback is higher than anintensity of the second thermal feedback, the first operating power maybe applied from an output start time point of the first thermalfeedback.

Herein, when performing the recognizing the cognitive enhancing power,the cognitive enhancing power may include the first operating power, andwhen an intensity of the first thermal feedback is lower than anintensity of the second thermal feedback, the first operating power maybe applied from an output start time point of the first thermalfeedback.

Herein, when performing the recognizing the cognitive enhancing power,when an intensity of the first thermal feedback is lower than anintensity of the second thermal feedback, the first excess power may beapplied from an output start time point of the first thermal feedback tothe first time point.

Herein, when performing the recognizing the cognitive enhancing power,when an intensity of the first thermal feedback is lower than anintensity of the second thermal feedback, a power having a voltage levelsmaller than the first operating power may be applied during apredetermined period of time from an output start time point of thefirst thermal feedback so that a temperature of the first contactsurface gradually reaches the first target temperature.

Herein, when performing the checking the second operating power, if itis confirmed that a direction of the first operating power and adirection of the second operating power is different, when performingthe recognizing the cognitive enhancing power, the cognitive enhancingpower may include the first operating power, and the first operatingpower may be applied from an output start time point of the firstthermal feedback.

Herein, when performing the checking the second operating power, if thefirst operating power is confirmed as a power for outputting coldfeedback to make the user feel cold, when performing the recognizing thecognitive enhancing power, the cognitive enhancing power may include thefirst operating power, and the first operating power may be applied froman output start time point of the first thermal feedback.

Herein, when performing the checking the second operating power, if thefirst operating power is confirmed as a power for outputting warmfeedback to make the user feel warm, when performing the recognizing thecognitive enhancing power, the first excess power may be applied from anoutput start time point of the first thermal feedback to the first timepoint.

According to another aspect of the present invention, a method forproviding a thermal feedback performed by a feedback device outputtingthe thermal feedback by transferring heat generated by a thermoelectricoperation to a user through a contact surface which contacts with theuser's body part by using a heat output module in which a plurality ofthermoelectric couple groups are arranged in one direction individuallyperforming the thermoelectric operation which includes at least one ofan exothermic operation and an endothermic operation may comprise:taking instruction to output the thermal feedback of a specificintensity of which a saturation temperature is a first temperaturesequentially from a first thermoelectric couple group to a Nththermoelectric couple group wherein the N is a natural number of 2 ormore; maintaining a temperature of a n−1th thermoelectric couple groupto a first temperature which is a thermoelectric couple groupneighboring a nth thermoelectric couple group wherein the n is a naturalnumber of N or less; instantaneously adjusting a temperature of the nththermoelectric couple group to a second temperature higher than thefirst temperature so that the user's cognition to a thermal feedbackcorresponding to the nth thermoelectric couple group is enhanced; andmaintaining a temperature of the nth thermoelectric couple group to thefirst temperature.

According to another aspect of the present invention, a method forproviding a thermal feedback performed by a feedback device outputtingthe thermal feedback by transferring heat generated by a thermoelectricoperation to a user through a contact surface which contacts with theuser's body part by using a heat output module in which a plurality ofthermoelectric couple groups are arranged in one direction individuallyperforming the thermoelectric operation which includes at least one ofan exothermic operation and an endothermic operation may comprise:taking instruction to output the thermal feedback of a specificintensity of which a saturation temperature is a first temperaturesequentially from a first thermoelectric couple group to a Nththermoelectric couple group wherein the N is a natural number of 2 ormore; applying a first voltage to a nth thermoelectric couple group forreaching a temperature of the nth thermoelectric couple group to asecond temperature which is a saturation temperature higher than thefirst temperature wherein the n is a natural number of less than N;applying a second voltage to the nth thermoelectric couple group forreaching a temperature of the nth thermoelectric couple group to thefirst temperature so that a temperature of the nth thermoelectric couplegroup is maintained to the first temperature when a temperature of thenth thermoelectric couple group reaches to a third temperature betweenthe first temperature and the second temperature; applying the firstvoltage to a n+1th thermoelectric couple group such that a temperatureof the n+1th thermoelectric couple group neighboring the nththermoelectric couple group reaches the third temperature after atemperature of the nth thermoelectric couple group becomes lower thanthe second temperature; and applying the second voltage to the nththermoelectric couple group so that a temperature of the n+1thermoelectric couple group is maintained to the first temperature whena temperature of the n+1 thermoelectric couple group reaches the thirdtemperature.

According to another aspect of the present invention, a feedback devicemay comprise: a heat output module outputting a thermal feedback bytransferring heat generated by a thermoelectric operation to a userthrough a contact surface comprising: a thermoelectric elementperforming a thermoelectric operation including at least one of anexothermic operation and an endothermic operation, a power terminalsupplying power to the thermoelectric element for the thermoelectricoperation and a contact surface which is provided on one side of thethermoelectric element and contacts with the user's body part, whereinthe thermoelectric element is provided by a thermoelectric couple arrayincluding a first thermoelectric couple group and a secondthermoelectric couple group which can be individually controllable; andwhen a second thermoelectric operation is initiated at the secondthermoelectric couple group and an output of a second thermal feedbackis initiated after a first thermoelectric operation is initiated at thefirst thermoelectric couple group and an output of a first thermalfeedback is initiated, a feedback controller applying excess power whichcauses an excess section in which a temperature of the secondthermoelectric couple group exceeds a saturation temperature accordingto an intensity of the second thermal feedback for a predetermined timepoint from an output start time point of the second thermal feedback sothat the user's cognition to the second thermal feedback is enhanced.

According to an aspect of the present invention, a thermal feedbackprovision method, which is performed by a feedback device configured tooutput a thermal feedback by transferring, to a user through a contactsurface in contact with the user's body part, heat generated by athermoelectric operation including at least one of an exothermicoperation and an endothermic operation of a thermoelectric element towhich power is applied, may include checking operating power applied tothe thermoelectric element in order to output the thermal feedback, theoperating power being determined according to the type and intensity ofthe thermal feedback; applying reduction power greater than theoperating power during a predetermined time after a time point at whichthe output of the thermal feedback is initiated to reduce the time ittakes for the temperature of the contact surface to reach a targettemperature corresponding to the type and intensity of the thermalfeedback; and applying the operating power to the thermoelectric elementafter the predetermined time elapses.

Herein, the reduction power may be in the same direction as theoperating power.

Herein, the applying of the reduction power may include applying thereduction power in the form of a duty signal.

Herein, in the applying of the reduction power, the temperature of thecontact surface may more quickly reach the target temperature when afirst reduction voltage having a first voltage magnitude is applied tothe thermoelectric element than when a second reduction voltage having asecond voltage magnitude, which is smaller than the first voltagemagnitude, is applied to the thermoelectric element.

Herein, in the applying of the reduction power, the temperature of thecontact surface may more quickly reach the target temperature when thereduction power is applied during a first time interval from the outputinitiation time point than when the reduction power is applied to thethermoelectric element during a second time interval, which is smallerthan the first time interval, from the output initiation time point.

Herein, the applying of the reduction power may include applying thereduction power so that the target temperature is not exceeded after thetemperature of the contact surface reaches the initial temperature.

Herein, the applying of the reduction power may include determining thevoltage magnitude of the reduction power so that the temperature of thecontact surface does not reach the target temperature during thepredetermined time during which the reduction power is applied.

Herein, the applying of the reduction power may include determining thepredetermined time so that the temperature of the contact surface doesnot reach the target temperature during the predetermined time duringwhich the reduction power is applied.

Herein, the applying of the reduction power may include applying thereduction power so that a temperature variation of the contact surfaceduring the predetermined time during which the reduction power isapplied is greater than a temperature variation of the contact surfaceafter the application of the reduction power is stopped.

Herein, the feedback device may adjust the intensity of the thermalfeedback to a plurality of intensities and may apply the reduction poweronly when the intensity of the thermal feedback is greater than or equalto a predetermined intensity.

Herein, the feedback device may adjust the intensity of the thermalfeedback to a plurality of intensities, and the thermal feedbackprovision method may further include acquiring the intensity of thethermal feedback; generating the operating power on the basis of theintensity of the thermal feedback; and determining whether to apply theend power according to whether the intensity of the thermal feedback isgreater than or equal to a predetermined intensity.

Herein, the thermoelectric element may be provided as a thermoelectriccouple array including a plurality of individually controllablethermoelectric couple groups, and the applying of the reduction powermay include applying the reduction power to at least one of theplurality of thermoelectric couple groups.

Herein, the checking of the operating power may include acquiringthermal feedback data from an external apparatus and checking theoperating power on the basis of the thermal feedback data.

Herein, the thermal feedback provision method of the present inventionmay further include acquiring thermal feedback data includinginformation regarding the time point at which the output of the thermalfeedback is initiated from an external apparatus, and the applying ofthe reduction power may include determining a time point at which thereduction power is applied to the thermoelectric element at a time pointpreceding the output initiation time point of the thermal feedbackincluded in the thermal feedback data in consideration that the time ittakes for the temperature of the contact surface to reach the targettemperature when the reduction power is applied is reduced and applyingthe reduction power at the time point at which the reduction power isapplied to the thermoelectric element.

According to another aspect of the present invention, a thermalexperience provision method may include reproducing multimedia contentincluding image data regarding a video and thermal feedback dataregarding a thermal feedback linked to a specific scene in the video,acquiring a thermoelectric operation initiation time point set as a timepoint preceding an output time point of the specific scene inconsideration of a delay time it takes for a user to sense the thermalfeedback after a thermoelectric operation for the thermal feedback isinitiated, and transmitting a feedback initiation message to a feedbackdevice that outputs the thermal feedback by transferring heat generatedin the thermoelectric element by the thermoelectric operation to theuser through a contact surface in contact with the user's body part whena reproduction time point of the multimedia content reaches thethermoelectric operation initiation time point and outputting thespecific scene through a display when the reproduction time point of themultimedia content reaches the output time point of the specific sceneso that the specific scene is provided to the user with linkage to thethermal feedback at the output time point of the specific scene, whereinthe acquiring of the thermoelectric operation initiation time pointincludes determining the thermoelectric operation initiation time point,considering that when the feedback device applies reduction power, whichis power for reducing a response time it takes for the temperature ofthe contact surface to reach a target temperature according to the typeand intensity of the thermal feedback, to the thermoelectric element,the delay time is reduced as the response time is reduced.

Herein, the delay time when the reduction power is applied from thefeedback device to the thermoelectric element may be shorter than thedelay time when the reduction power is not applied from the feedbackdevice to the thermoelectric element.

Herein, the thermoelectric operation initiation time point may precedethe reproduction time point of the specific scene by the delay time.

According to another aspect of the present invention, a feedback devicemay include a heat output module including a thermoelectric elementconfigured to perform a thermoelectric operation including at least oneof an exothermic operation and an endothermic operation, a powerterminal configured to supply power for the thermoelectric operation tothe thermoelectric element, and a contact surface provided on one sidesurface of the thermoelectric element to come into contact with a user'sbody part, the heat output module being configured to output a thermalfeedback by transferring the heat generated by the thermoelectricoperation to the user through the contact surface and include a feedbackcontroller configured to check operating power applied to thethermoelectric element in order to output the thermal feedback, theoperating power being determined according to the type and intensity ofthe thermal feedback and configured to apply reduction power greaterthan the operating power during a predetermined time after a time pointat which the output of the thermal feedback is initiated to reduce thetime it takes for the temperature of the contact surface to reach atarget temperature corresponding to the type and intensity of thethermal feedback.

According to another aspect of the present invention, a feedback devicethat provides a thermal feedback for providing a thermal experienceaccompanied by multimedia content with linkage to a content reproductiondevice for driving the multimedia content may include a communicationmodule configured to communicate with the content reproduction device; aheat output module including a thermoelectric element configured toperform a thermoelectric operation including at least one of anexothermic operation and an endothermic operation, a power terminalconfigured to supply power for the thermoelectric operation to thethermoelectric element, and a contact surface provided on one sidesurface of the thermoelectric element to come into contact with a user'sbody part, the heat output module being configured to output a thermalfeedback by transferring the heat generated by the thermoelectricoperation to the user through the contact surface; and a feedbackcontroller configured to receive information regarding the thermalfeedback from the content reproduction device through the communicationmodule, select an operating voltage from among a plurality ofpredetermined voltages on the basis of the intensity of the thermalfeedback corresponding to the information regarding the thermalfeedback, acquire a reduction voltage higher than the operating voltage,and apply the reduction voltage during a predetermined time from a timepoint at which the output of the thermal feedback is initiated to reducethe time it takes for the temperature of the contact surface to reach atarget temperature corresponding to the intensity of the thermalfeedback.

According to another aspect of the present invention, a gamingcontroller that acquires a user's manipulation used for multimediacontent including a game and a haptic application and provides a thermalfeedback for providing a thermal experience accompanied by themultimedia content with linkage to a content reproduction device fordriving the multimedia content may include a casing configured to forman outer appearance of the gaming controller, the casing including agrip part grasped by the user; an input module configured to receive auser input according to the user's manipulation; a communication moduleconfigured to communicate with the content reproduction device; a heatoutput module including a thermoelectric element configured to perform athermoelectric operation, a power terminal configured to supply power tothe thermoelectric element, and a contact surface provided at the grippart and configured to transfer heat generated by the thermoelectricoperation of the thermoelectric element to the user, the heat outputmodule being configured to output the thermal feedback by transferringthe heat generated by the thermoelectric operation to the user throughthe contact surface; and a controller configured to acquire the userinput received through the input module, transmit the user input to thecontent reproduction device through the communication module, receiveinformation regarding the thermal feedback from the content reproductiondevice through the communication module, select an operating voltagefrom among a plurality of predetermined voltages on the basis of theintensity of the thermal feedback corresponding to the informationregarding the thermal feedback, acquire a reduction voltage higher thanthe operating voltage, and apply the reduction voltage during apredetermined time from a time point at which the output of the thermalfeedback is initiated to reduce the time it takes for the temperature ofthe contact surface to reach a target temperature corresponding to theintensity of the thermal feedback.

According to another aspect of the present invention, a thermal feedbackprovision method, which is performed by a feedback device configured tooutput a thermal feedback by transferring, to a user through a contactsurface in contact with the user's body part, heat generated by athermoelectric operation including at least one of an exothermicoperation and an endothermic operation of a thermoelectric element towhich power is applied, may include applying operating power to thethermoelectric element in order to output the thermal feedback; checkinga time point at which the thermal feedback ends; applying end power forstopping the output of the thermal feedback to the thermoelectricelement so that a rate at which the temperature of the contact surfacechanged according to the output of the thermal feedback reaches aninitial temperature, which is a temperature before the output of thethermal feedback is initiated, during a predetermined time from the timepoint at which the thermal feedback ends; and stopping application ofthe end power after the predetermined time elapses.

Herein, the end power may be in the opposite direction to the operatingpower.

Herein, the end power may be in the opposite direction to the operatingpower, and the end power may have the same voltage magnitude as theoperating power.

Herein, the end power may be in the opposite direction to the operatingpower, and the end power may have a different voltage magnitude from theoperating power.

Herein, the applying of the end power may include applying the end powerin the form of a duty signal.

Herein, in the applying of the end power, the temperature of the contactsurface may more quickly reach the initial temperature when a first endvoltage having a first voltage magnitude is applied to thethermoelectric element than when a second end voltage having a secondvoltage magnitude, which is smaller than the first voltage magnitude, isapplied to the thermoelectric element.

Herein, in the applying of the end power, the temperature of the contactsurface may more quickly reach the initial temperature when the endvoltage is applied during a first time interval from the end time pointthan when the end voltage is applied to the thermoelectric elementduring a second time interval, which is smaller than the first timeinterval, from the end time point.

Herein, the applying of the end power may include applying the end powerso that the initial temperature is not exceeded after the temperature ofthe contact surface reaches the initial temperature.

Herein, the applying of the end power may include determining thevoltage magnitude of the end power so that the temperature of thecontact surface does not reach the initial temperature during thepredetermined time during which the end power is applied.

Herein, the applying of the end power may include determining thepredetermined time so that the temperature of the contact surface doesnot reach the initial temperature during the predetermined time duringwhich the end power is applied.

Herein, when the thermal feedback is a hot feedback for making the userfeel a hot sensation, the operating voltage may be a forward voltagecausing the exothermic operation in the thermoelectric element, and theend voltage may be a reverse voltage being applied in the oppositedirection to the forward voltage.

Herein, when the thermal feedback is a cold feedback for making the userfeel a cold sensation, the operating voltage may be a reverse voltagecausing the endothermic operation in the thermoelectric element, and theend voltage may be a forward voltage being applied in the oppositedirection to the reverse voltage.

Herein, the thermoelectric element may be provided as a thermoelectriccouple array including a plurality of individually controllablethermoelectric couple groups, and the applying of the end power mayinclude applying the end power to at least one of the plurality ofthermoelectric couple groups.

Herein, when the thermal feedback is a thermal grill feedback that makesthe user feel a pain sensation, the thermoelectric couple array mayinclude a first thermoelectric couple group and a second thermoelectriccouple group that are individually controllable. In the applying of theoperating power to the thermoelectric element, a first forward voltagecausing the exothermic operation in the first thermoelectric couplegroup may be applied to the first thermoelectric couple group, and afirst reverse voltage causing the endothermic operation in the firstthermoelectric couple group may be applied to the second thermoelectriccouple group. In the applying of the end power, a second reverse voltagebeing applied in the opposite direction to the first forward voltage maybe applied to the first thermoelectric couple group, and a secondforward voltage being applied in the opposite direction to the firstreverse voltage may be applied to the second thermoelectric couplegroup.

Herein, the checking of the end time point may include acquiring thermalfeedback data including information regarding at least one of the typeor intensity of the thermal feedback from an external apparatus andchecking the end time point on the basis of the thermal feedback data.

Herein, when a first thermal feedback and then a second thermal feedbackare output from the feedback device, the applying of the operating powerto the thermoelectric element may include determining a time point atwhich the application of the operating power for outputting the secondthermal feedback is applicable to the thermoelectric element accordingto the time it takes for the temperature of the contact surface to reachthe initial temperature after the output of the first thermal feedbackends.

Herein, the applying of the end power may include applying the end powerso that a temperature variation of the contact surface during thepredetermined time during which the end power is applied is greater thana temperature variation of the contact surface after the application ofthe end power is stopped.

Herein, the feedback device may adjust the intensity of the thermalfeedback to a plurality of intensities and may apply the end power onlywhen the intensity of the thermal feedback is greater than or equal to apredetermined intensity.

Herein, the feedback device may adjust the intensity of the thermalfeedback to a plurality of intensities, and the thermal feedbackprovision method may further include acquiring the intensity of thethermal feedback, generating the operating power on the basis of theintensity of the thermal feedback, and determining whether to apply theend power according to whether the intensity of the thermal feedback isgreater than or equal to a predetermined intensity.

According to another aspect of the present invention, a feedback devicemay include a heat output module including a thermoelectric elementconfigured to perform a thermoelectric operation including at least oneof an exothermic operation and an endothermic operation, a powerterminal configured to supply power for the thermoelectric operation tothe thermoelectric element, and a contact surface provided on one sidesurface of the thermoelectric element to come into contact with a user'sbody part, the heat output module being configured to output a thermalfeedback by transferring the heat generated by the thermoelectricoperation to the user through the contact surface and include a feedbackcontroller configured to apply operating power to the thermoelectricelement in order to output the thermal feedback and configured to applyend power for stopping the output of the thermal feedback to thethermoelectric element at a first time point so that the temperature ofthe contact surface changed according to the output of the thermalfeedback quickly reaches an initial temperature, which is a temperaturebefore the output of the thermal feedback is initiated, when the outputof the thermal feedback ends.

According to another aspect of the present invention, a feedback devicethat provides a thermal feedback for providing a thermal experienceaccompanied by multimedia content with linkage to a content reproductiondevice for driving the multimedia content may include a communicationmodule configured to communicate with the content reproduction device; aheat output module including a thermoelectric element configured toperform a thermoelectric operation including at least one of anexothermic operation and an endothermic operation, a power terminalconfigured to supply power for the thermoelectric operation to thethermoelectric element, and a contact surface provided on one sidesurface of the thermoelectric element to come into contact with a user'sbody part, the heat output module being configured to output a thermalfeedback by transferring the heat generated by the thermoelectricoperation to the user through the contact surface; and a feedbackcontroller configured to receive information regarding the thermalfeedback from the content reproduction device through the communicationmodule, select an operating voltage from among a plurality ofpredetermined voltages on the basis of the intensity of the thermalfeedback corresponding to the information regarding the thermalfeedback, generate operating power on the basis of the operatingvoltage, apply the operating power to the power terminal so that theheat output module outputs the thermal feedback, and apply, to thethermoelectric element, end power for stopping output of the thermalfeedback at a first time point so that the temperature of the contactsurface increasing along with the output of the thermal feedback quicklyreaches an initial temperature, which is a temperature before the outputof the thermal feedback is initiated when the output of the thermalfeedback ends.

According to another aspect of the present invention, a gamingcontroller that acquires a user's manipulation used for multimediacontent including a game and a haptic application and provides a thermalfeedback for providing a thermal experience accompanied by themultimedia content with linkage to a content reproduction device fordriving the multimedia content may include a casing configured to forman outer appearance of the gaming controller, the casing including agrip part grasped by the user; an input module configured to receive auser input according to the user's manipulation; a communication moduleconfigured to communicate with the content reproduction device; a heatoutput module including a thermoelectric element configured to perform athermoelectric operation, a power terminal configured to supply power tothe thermoelectric element, and a contact surface provided at the grippart and configured to transfer heat generated by the thermoelectricoperation of the thermoelectric element to the user, the heat outputmodule being configured to output the thermal feedback by transferringthe heat generated by the thermoelectric operation to the user throughthe contact surface; and a controller configured to acquire the userinput received through the input module, transmit the user input to thecontent reproduction device through the communication module, receiveinformation regarding the thermal feedback from the content reproductiondevice through the communication module, select an operating voltagefrom among a plurality of predetermined voltages on the basis of theintensity of the thermal feedback corresponding to the informationregarding the thermal feedback, generate operating power on the basis ofthe operating voltage, apply the operating power to the power terminalso that the heat output module outputs the thermal feedback, and apply,to the thermoelectric element, end power for stopping output of thethermal feedback at a first time point so that the temperature of thecontact surface increasing along with the output of the thermal feedbackquickly reaches an initial temperature, which is a temperature beforethe output of the thermal feedback is initiated when the output of thethermal feedback ends.

1. Thermal Experience Providing System

A thermal experience providing system 1000 according to an embodiment ofthe present invention will be described below.

1.1. Overview of Thermal Experience Providing System

A thermal experience providing system 1000 according to an exemplaryembodiment of the present invention is a system which allows a user toexperience a thermal experience (TX). Specifically, the thermalexperience providing system 1000 may allow a user to experience athermal experience by outputting thermal feedback as a part of a formedof a representation of content when multimedia content is reproduced.

Herein, the thermal feedback is a kind of thermal stimulation whichallows a user to feel a thermal sensation by stimulating thermal sensoryorgans mainly distributed in a user's body and in the presentspecification the thermal feedback should be interpreted to include allthe thermal stimuli which stimulate a thermal sensory system of theuser.

Representative examples of the thermal feedback include hot feedback andcold feedback. The hot feedback means thermal feedback which allows auser to feel a hot sensation by applying hot heat to a hot spotdistributed on a user's skin and the cold feedback means thermalfeedback which allows a user to feel a cold sensation by applying coldheat to a cold spot distributed on a user's skin.

Herein, since the heat is a physical quantity represented by a scalarform, the expression, “applying cold heat,” or “transferring cold heat,”may not be an exact expression from a physical point of view. However,for convenience of description in the present description, a phenomenonin which heat is applied or transferred is expressed as “applying hotheat” or “transferring hot heat”, and a phenomenon opposite to thephenomenon, i.e., a phenomenon in which heat is absorbed is expressed as“applying cold heat” or “transferring cold heat”.

In addition, the thermal feedback in the present specification mayfurther include thermal grill feedback in addition to the hot feedbackand the cold feedback. When the hot heat and the cold heat are appliedat the same time, a user perceives a pain sensation instead ofindividually perceiving a hot sensation and a cold sensation. The painsensation is referred to as a so-called thermal grill illusion (TGI)(hereinafter, referred to as a “thermal pain sensation”). That is,thermal grill feedback means thermal feedback in which a combination ofhot heat and cold heat is applied, and may be provided mainly byconcurrently outputting the hot feedback and the cold feedback. Inaddition, the thermal grill feedback may be referred to as “thermal painsensation feedback” in terms of providing a sensation close to pain. Thethermal feedback will be described below in detail.

Herein, the multimedia content may include various kinds of contentincluding a video, a game, a virtual reality application, and anaugmented reality application.

In general, the multimedia content is provided to a user mainly inaccordance with an audiovisual expression form based on an image and avoice. However, in the present invention, a thermal expression based onthe above-mentioned thermal feedback may be included as an essentialexpression form.

Meanwhile, the “reproduction” of multimedia content should beinterpreted to include all operations of executing and representing themultimedia content to a user. Therefore, the term “reproduction” in thepresent specification should be interpreted to include not only anoperation of simply playing a video through a media player but also alloperations of executing a game program, a training program, a virtualreality application, an augmented reality application, and the like.

1.2. Configuration of Thermal Experience Providing System

FIG. 1 is a block diagram showing a configuration of a thermalexperience providing system 1000 according to an embodiment of thepresent invention.

Referring to FIG. 1, the thermal experience providing system 1000 mayinclude a content reproduction device 1200, an audiovisual device 1400,and a feedback device 1600.

Herein, the content reproduction device 1200 may reproduce multimediacontent, the audiovisual device 1400 may output an image or voiceaccording to content reproduction, and the feedback device 1600 mayoutput a thermal feedback according to content reproduction.

For example, the content reproduction device 1200 may decode videocontent including image data, voice data, or thermal feedback data andmay deliver an image signal, a voice signal, or a thermal feedbacksignal to the audiovisual device 1400 and the feedback device 1600. Theaudiovisual device 1400 may receive an image signal and a voice signaland then output images and voice, and the feedback device 1600 mayreceive a thermal feedback signal and then output a thermal feedback.

The components of the thermal experience providing system 1000 will bedescribed below in more detail.

1.2.1. Content Reproduction Device

The content reproduction device 1200 reproduces multimedia content.

FIG. 2 is a block diagram showing the content reproduction device 1200according to an embodiment of the present invention.

Referring to FIG. 2, the content reproduction device 1200 may include acommunication module 1220, a memory 1240, and a controller 1260.

The communication module 1220 may communicate with an externalapparatus. The content reproduction device 1200 may transmit or receivedata to or from the audiovisual device 1400 or the feedback device 1600through the communication module 1220. For example, through thecommunication module 1220, the content reproduction device 1200 maydeliver an A/V signal to the audiovisual device 1400 or deliver athermal feedback signal to the feedback device 1600. In addition, thecontent reproduction device 1200 may access the Internet through thecommunication module 1220 and then download multimedia content.

The communication module 1220 is largely divided into a wiredcommunication module and a wireless communication module. Since thewired communication module and the wireless communication module eachhave advantages and disadvantages, the content reproduction device 1200may be provided with both of the wired communication module and thewireless communication module.

Typically, the wired communication module may use, for example, localarea network (LAN), universal serial bus (USB) communication, or otherschemes.

The wireless communication module may use a wireless personal areanetwork (WPAN)-based communication scheme such as Bluetooth or Zigbee.However, since a wireless communication protocol is not limited thereto,the wireless communication module may use a wireless local area network(WLAN)-based communication scheme such as Wi-Fi or other knowncommunication schemes.

Meanwhile, as the wired/wireless communication protocol, an independentprotocol developed by a game console manufacturer may be used.

The memory 1240 may store various kinds of information. The memory 1240may temporarily or semi-permanently store data. Examples of the memory1240 may include a hard disk drive (HDD), a solid state drive (SSD), aflash memory, a read-only memory (ROM), a random access memory (RAM),etc. The memory 1240 may be built into, or detachable from, the contentreproduction device 1200.

An operating system (OS) for driving the content reproduction device1200 or various kinds of data needed for operation of the contentreproduction device 1200 in addition to content to be executed by thecontent reproduction device 1200 may be stored in the memory 1240.

The controller 1260 may control overall operation of the contentreproduction device 1200. For example, the controller 1260 may load orreproduce multimedia content from the memory 1240 or may generate acontrol signal for controlling an image or voice or a thermal feedbackoutput according to content reproduction.

The controller 1260 may be implemented as a central processing unit(CPU) or the like in hardware, software, or a combination thereof. Thecontroller 1260 may be provided in the form of an electronic circuit forprocessing an electric signal to perform a control function when beingimplemented in hardware and may be provided in the form of a program orcodes for driving a hardware circuit when being implemented in software.

1.2.2. Audiovisual Device

The audiovisual device 1400 may output images and voice according tomultimedia reproduction.

FIG. 3 is a block diagram showing a configuration of the audiovisualdevice 1400 according to an embodiment of the present invention.

Referring to FIG. 3, the audiovisual device 1400 may include acommunication module 1420 and an A/V module 1440.

The communication module 1420 may communicate with an externalapparatus.

The audiovisual device 1400 may transmit or receive data to or from thecontent reproduction device 1200 through the communication module 1420.For example, the audiovisual device 1400 may receive an A/V signal fromthe content reproduction device 1200 or the feedback device 1600 throughthe communication module 1420.

The communication module 1420 of the audiovisual device 1400 may besimilar to the communication module 1220 of the content reproductiondevice 1200, and thus a detailed description thereof will be omitted.

The A/V module 1440 may provide images or voice to a user. To this end,the A/V module 1440 may include a video module 1442 and an audio module1444.

The video module 1442 may be generally provided in the form of a displayand may output an image according to an image signal received from thecontent reproduction device 1200 or the feedback device 1600. The audiomodule 1444 may be generally provided in the form of a speaker and mayoutput voice according to a voice signal received from the contentreproduction device 1200 or the feedback device 1600.

1.2.3. Feedback Device

The feedback device 1600 may output a thermal feedback according tomultimedia reproduction.

FIG. 4 is a block diagram showing a configuration of the feedback device1600 according to an embodiment of the present invention.

Referring to FIG. 4, the feedback device 1600 may include acommunication module 1620 and a heat output module 1640.

According to an embodiment of the present invention, a feedbackcontroller 1648 may be either separate from or included in the heatoutput module 1640. Also, the present invention is not limited thereto,and when the feedback controller 1648 is present outside the heat outputmodule 1640, a separate feedback controller may be present inside theheat output module 1640 independently of the feedback controller 1648.In this specification, for convenience of description, it will bepresumed that the feedback controller 1648 is included in the heatoutput module 1640.

The communication module 1620 may communicate with an externalapparatus. The feedback device 1600 may transmit or receive data to orfrom the content reproduction device 1200 through the communicationmodule 1620. For example, the feedback device 1600 may receive thermalfeedback data from the content reproduction device 1200 through thecommunication module 1620. As another example, the feedback device 1600may transmit a voice signal and/or an image signal to the audiovisualdevice 1400 through the communication module 1620.

The heat output module 1640 may output a thermal feedback. The thermalfeedback may be output by the heat output module 1640, which includes acontact surface 1641 brought into contact with a user's body and athermoelectric element connected to the contact surface 1641, applyinghot heat or cold heat, which is generated in the thermoelectric elementwhen power is applied, to the user's body through the contact surface1641.

The heat output module 1640 may perform an exothermic operation,endothermic operation, or thermal grill operation according to thethermal feedback data received from the content reproduction device 1200through the communication module 1620 to output a thermal feedback, andthe user may experience a thermal experience by the output thermalfeedback.

A detailed configuration or operation scheme of the heat output module1640 will be described below in more detail.

2. Heat Output Module

The heat output module 1640 according to an embodiment of the presentinvention will be described below.

2.1. Overview of Heat Output Module

A heat output module 1640 may output thermal feedback for transferringhot heat and cold heat to a user by performing an exothermic operation,an endothermic operation, or a thermal grill operation. In a thermalexperience providing system 1000, when a feedback device 1600 receives athermal feedback signal, the heat output module 1640 mounted on thefeedback device 1600 may output thermal feedback to allow the thermalexperience providing system 1000 to provide thermal experience to auser.

In order to perform the above-described exothermic operation,endothermic operation, or thermal grill operation, the heat outputmodule 1640 may use a thermoelectric element such as a Peltier element.

The Peltier effect is a thermoelectric phenomenon discovered by JeanPeltier in 1834. According to the Peltier effect, when an electriccurrent is made to flow through a junction between dissimilar metals, anexothermic reaction occurs at one side of the junction and anendothermic reaction occurs at the other side of the junction accordingto a current direction. The Peltier element is an element which causessuch a Peltier effect. The Peltier element was originally made of ajoined body of dissimilar metals such as bismuth and antimony. However,recently, the Peltier element has been manufactured through a method ofdisposing N-P semiconductors between two metal plates so as to havehigher thermoelectric efficiency.

When a current is applied to the Peltier element, heat generation andheat absorption may instantaneously occur at both metal plates, aswitching between the heat generation and the heat absorption may bemade according to a current direction, and a degree of the heatgeneration or absorption may be relatively precisely adjusted accordingto a current amount. Thus, the Peltier element is suitable to be usedfor an exothermic operation or an endothermic operation for thermalfeedback. In particular, recently, as a flexible thermoelectric elementhas been developed, it has been possible to manufacture the flexiblethermoelectric element in a form with which a user's body easily comesinto contact therewith such that commercial availability of the flexiblethermoelectric element as the feedback device 1600 has been increasing.

Therefore, as electricity is applied to the above-describedthermoelectric element, the heat output module 1640 may perform anexothermic operation or an endothermic operation. Physically, anexothermic reaction and an endothermic reaction concurrently occur inthe thermoelectric element to which electricity is applied. However, inthe present specification, in the case of the heat output module 1640,an operation in which a surface in contact with a user's body generatesheat is defined as an exothermic operation, and an operation in whichthe surface in contact with the user's body absorbs heat is defined asan endothermic operation. For example, the thermoelectric element may bemanufactured by disposing N-P semiconductors on a substrate 1642. When acurrent is applied to the thermoelectric element, heat generation occursat one side of the thermoelectric element, and heat absorption occurs atthe other side of the thermoelectric element. When one side of thethermoelectric element facing the user's body is defined as a front sideand a side opposite to the one side is defined as a rear side, anoperation in which the heat generation occurs at the front side and anoperation in which the heat absorption occurs at the rear side may bedefined as an operation in which the heat output module 1640 performs anexothermic operation. On the contrary, an operation in which the heatabsorption occurs at the front side and the heat generation occurs atthe rear side may be defined as an operation in which the heat outputmodule 1640 performs an endothermic operation.

In addition, since a thermoelectric effect is induced by electriccharges flowing in the thermoelectric element, it is possible todescribe electricity inducing the exothermic operation or theendothermic operation of the heat output module 1640 in terms of acurrent. In the present specification, however, for convenience ofdescription, description will be made mainly in terms of a voltage. Thisis merely for convenience of description, and inventive thinking is notrequired for a person having ordinary skill in the art to which thepresent invention belongs (hereinafter referred to as “a person skilledin the art”) to interpret the exothermic operation or the endothermicoperation in terms of a current. Therefore, the present invention is notlimited to expression in terms of the voltage.

2.2. Configuration of Heat Output Module

FIG. 5 is a block diagram showing a configuration of the heat outputmodule 1640 according to an embodiment of the present invention.

Referring to FIG. 5, the heat output module 1640 may include a contactsurface 1641, a substrate 1642, a thermoelectric couple array 1643disposed on the substrate 1642, a power terminal 1647 configured toapply power to the heat output module 1640, and a feedback controller1648.

The contact surface 1641 is directly brought into contact with theuser's body to transfer hot heat or cold heat generated in the heatoutput module 1640 to the user's skin. In other words, a portion of theouter surface of the feedback device 1600 that is directly brought intocontact with the user's body may be used as the contact surface 1641.For example, the contact surface 1641 may be formed in a grip part,which is a part of the casing of the feedback device 1600 the usergrasps.

As an example, the contact surface 1641 may be provided as a layer thatis directly or indirectly attached to the outer surface (toward theuser's body) of the thermoelectric couple array 1643 of the heat outputmodule 1640 where an exothermic operation or endothermic operation isperformed. This type of contact surface 1641 may be disposed between theuser's skin and the thermoelectric couple array to perform heattransfer. To this end, the contact surface 1641 may be made of amaterial with high thermal conductivity to facilitate transfer of heatfrom the thermoelectric couple array 1643 to the user's body. Also, thelayer-type contact surface 1641 also prevents direct exposure of thethermoelectric couple array 1643, thereby protecting the thermoelectriccouple array 1643 from external impacts.

In the above description, the contact surface 1641 is disposed on theouter surface of the thermoelectric couple array 1643. However, theouter surface of the thermoelectric couple array 1643 itself may be thecontact surface 1641. In other words, some or all of the front surfaceof the thermoelectric couple array 1643 may be used as the contactsurface 1641.

The substrate 1642 serves to support a unit thermoelectric couple 1645and is made of an insulating material. For example, ceramic may beselected as the material of the substrate 1642. The substrate 1642 maybe of a flat plate shape, but it is not necessarily so.

The substrate 1642 may be made of a flexible material to haveflexibility that may be used universally for several kinds of feedbackdevices 1600 having contact surfaces 1641 of various shapes. Forexample, for a gaming controller-type feedback device 1600, generally, aportion of the gamming controller a user grasps with the palm may becurved. In order to use the heat output module 1640 at the curvedportion, it may be important that the heat output module 1640 hasflexibility. To this end, the flexible material used for the substrate1642 may be, for example, glass fiber or flexible plastic.

The thermoelectric couple array 1643 may be composed of a plurality ofunit thermoelectric couples 1645 disposed on the substrate 1642. Theunit thermoelectric couples 1645 may use different metal couples (e.g.,Bismuth and Antimony, etc.), but N-type and P-type semiconductor couplesmay be used mainly.

In the unit thermoelectric couples 1645, the semiconductor couples maybe electrically connected to each other at one end and may beelectrically connected to the unit thermoelectric couples 1645 at theother end. Electrical connection between a couple of semiconductors 1645a and 1645 b or with an adjacent semiconductor may be accomplished by aconductor member 1646 disposed on the substrate 1642. The conductormember 1646 may be a lead or an electrode made of copper, silver, or thelike.

Electrical connection of the unit thermoelectric couples 1645 may bemainly accomplished as a serial connection, and the unit thermoelectriccouples 1645 connected in series to one another may form thethermoelectric couple group 1644, and such thermoelectric couple groups1644 may form the thermoelectric couple array 1643.

The power terminal 1647 may apply power to the heat output module 1640.The thermoelectric couple array 1643 may dissipate or absorb heataccording to a voltage magnitude and a current direction of the powerapplied to the power terminal 1647. In more detail, two such powerterminals 1647 may be connected to each of the thermoelectric couplegroups 1644. Accordingly, when there are several thermoelectric couplegroups 1644, two power terminals 1647 may be disposed for each of thethermoelectric couple groups 1644. According to such a connectionscheme, a voltage magnitude or a current direction may be individuallycontrolled for each of the thermoelectric couple groups 1644 todetermine whether to perform an exothermic operation or an endothermicoperation and adjust a degree to which the exothermic operation orendothermic operation is performed.

As will be described later, the power terminal 1647 may receive anelectric signal output by the feedback controller 1648. As a result, thefeedback controller 1648 may adjust the direction or size of theelectric signal to control the exothermic operation and the endothermicoperation of the heat output module 1640. Also, when there are aplurality of thermoelectric couple groups 1644, electric signals appliedto power terminals 1647 may be individually adjusted to individuallycontrol the thermoelectric couple groups 1644.

The feedback controller 1648 may apply electric signals to thethermoelectric couple array 1643 through the power terminals 1647. Indetail, the feedback controller 1648 may receive information regarding athermal feedback from the controller 1260 of the content reproductiondevice 1200 through the communication module 1620, interpret theinformation regarding the thermal feedback to determine the type orintensity of the thermal feedback, and allow the thermoelectric couplearray 1643 to output the thermal feedback by generating an electricsignal and applying the electric signal to the power terminals 1647according to a result of the determination.

To this end, the feedback controller 1648 may compute and processvarious kinds of information and output an electric signal to thethermoelectric couple array 1643 according to a result of the processingto control operation of the thermoelectric couple array 1643.Accordingly, the feedback controller 1648 may be implemented as acomputer or the like in hardware, software, or a combination thereof.The feedback controller 1648 may be provided in the form of anelectronic circuit for processing an electric signal to perform acontrol function when being implemented in hardware and may be providedin the form of a program or codes for driving a hardware circuit whenbeing implemented in software.

Such a plurality of heat output modules 1640 may be provided to thefeedback device 1600. For example, when the feedback device 1600 has aplurality of grip parts, each of the grip parts of the feedback device1600 may be equipped with the heat output module 1640. When a pluralityof heat output modules 1640 are provided to a single feedback device1600, a feedback controller may be provided for each of the heat outputmodules 1640 of the feedback device 1600 or a single feedback controllerfor managing all the heat output modules 1640 may be provided in anintegrated manner. Also, when a plurality of feedback devices 1600 areprovided in the thermal experience providing system 1000, one or moreheat output modules 1640 may be disposed in each of the feedback devices1600.

2.3. Aspect of Heat Output Module

Some exemplary aspects of the heat output module 1640 will be describedbased on the above description of the configuration of the heat outputmodule 1640.

FIG. 6 is a diagram showing an aspect of the heat output module 1640according to an embodiment of the present invention.

Referring to FIG. 6, according to an aspect of the heat output module1640, a pair of substrates 1642 may be provided to face each other. Acontact surface 1641 may be located outside one of the two substrates1642 to transfer heat generated in the heat output module 1640 to auser's body. Also, when a flexible substrate 1642 is used as thesubstrate 1642, flexibility may be imparted to the heat output module1640.

A plurality of unit thermoelectric couples 1645 are located between thesubstrates 1642. Each of the unit thermoelectric couples 1645 may becomposed of a semiconductor couple of an N-type semiconductor and aP-type semiconductor. In each of the unit thermoelectric couples 1645,the N-type semiconductor and the P-type semiconductor are electricallyconnected to each other at one ends by a conductor member 1646. Also,the other ends of the N-type semiconductor and the P-type semiconductorof any unit thermoelectric couple 1645 are connected to the other endsof N-type semiconductor and the P-type semiconductor of an adjacent unitthermoelectric couple 1645, and thus electrical connection between theunit devices is accomplished through the conductor member 1646. Thus,the unit connection devices are connected in series to form a singlethermoelectric couple group 1644. According to this aspect, the entirethermoelectric couple array 1643 is formed as a single thermoelectriccouple group 1644, and all the unit thermoelectric couples 1645 areconnected in series to each other between power terminals 1647. Thus,the heat output module 1640 performs the same operation over the entirefront surface. That is, the heat output module 1640 may perform anexothermic operation when power is applied to the power terminals 1647in one direction and may perform an endothermic operation when power isapplied to the power terminals 1647 in the opposite direction.

FIG. 7 is a diagram showing another aspect of the heat output module1640 according to an embodiment of the present invention.

Referring to FIG. 7, the other aspect of the heat output module 1640 issimilar to the above-described one aspect. However, according to thisaspect, a thermoelectric couple array 1643 has a plurality ofthermoelectric couple groups 1644, each of which is connected to acorresponding power terminal 1647. Thus, the thermoelectric couplegroups 1644 may be individually controlled. For example, referring toFIG. 7, by applying electric current to a first thermoelectric couplegroup 1644 and a second thermoelectric couple group 1644 in differentdirections, the first thermoelectric couple group 1644 may perform anexothermic operation (in this case, the direction of electric current isset to “forward”), and also the second thermoelectric couple group 1644may perform an endothermic operation (in this case, the direction ofelectric current is set to “reverse”). As another example, by applyingdifferent voltage magnitudes to a power terminal 1647 of the firstthermoelectric couple group 1644 and a power terminal 1647 of the secondthermoelectric couple group 1644, the first thermoelectric couple group1644 and the second thermoelectric couple group 1644 may perform anexothermic operation or an endothermic operation to different degrees.

In FIG. 7, it is shown that the thermoelectric couple groups 1644 arearranged in the thermoelectric couple array 1643 in one dimension.However, the thermoelectric couple groups 1644 may be arranged in twodimensions. FIG. 8 is a diagram showing still another aspect of the heatoutput module 1640 according to an embodiment of the present invention.Referring to FIG. 8, when thermoelectric couple groups 1644 disposed intwo dimensions are used, operation control may be performed individuallyfor more-segmented regions.

Also, according to the aspects of the heat output module 1640, it hasbeen described that a pair of substrates 1642 facing each other areused, but a single substrate 1642 may be used. FIG. 9 is a diagramshowing still another aspect of the heat output module 1640 according toan embodiment of the present invention. Referring to FIG. 9, unitthermoelectric couples 1656 and conductor members 1646 may be disposedin a single substrate 1642 by being buried into the substrate 1642. Tothis end, glass fiber may be used as the substrate 1642. When the singlesubstrate 1642 according to this aspect is used, higher flexibility maybe imparted to the heat output module 1640.

The various aspects of the heat output module 1640 may be combined ormodified within the scope of what is obvious to those skilled in theart. For example, according to each aspect of the heat output module1640, it has been described that the contact surface 1641 is formed onthe front surface of the heat output module 1640 as a layer separatefrom the heat output module 1640, but the front surface of the heatoutput module 1640 itself may be used as the contact surface 1641. Forexample, according to an aspect of the heat output module 1640, an outersurface of the substrate 1642 may be used as the contact surface 1641.

2.4. Output of Thermal Feedback

A thermal feedback output operation performed by the feedback device1600 will be described below.

The feedback device 1600 may output a thermal feedback as the heatoutput module 1640 performs an exothermic operation or an endothermicoperation. The thermal feedback may include a hot feedback, a coldfeedback, and a thermal grill feedback.

Herein, the hot feedback may be output by the heat output module 1640performing an exothermic operation, and the cold feedback may be outputby the heat output module 1640 performing an endothermic operation.Also, the thermal grill feedback may be output through a thermal grilloperation in which the exothermic operation and the endothermicoperation are combined.

The feedback device 1600 may output the thermal feedback at variousintensities. The intensity of the thermal feedback may be adjusted by afeedback controller 1648 of the heat output module 1640 adjusting themagnitude of a voltage applied to a thermoelectric couple array 1643through a power terminal 1647. Here, the method of adjusting themagnitude of a voltage includes a method of smoothing a duty signal andthen applying power to a thermoelectric element. That is, the adjustmentof the magnitude of a voltage may be regarded as including adjustment ofthe magnitude of a voltage by adjusting a duty rate of the duty signal.

The exothermic operation, the endothermic operation, and the thermalgrill operation will be described below in more detail.

2.4.1. Exothermic/Endothermic Operation

The feedback device 1600 may perform an exothermic operation with theheat output module 1640 to provide a hot feedback to a user. Similarly,the feedback device 1600 may perform an endothermic operation to providea cold feedback to a user.

FIG. 10 is a diagram showing an exothermic operation for providing a hotfeedback according to an embodiment of the present invention, and FIG.11 is a graph showing the intensity of a hot feedback according to anembodiment of the present invention.

Referring to FIG. 10, the exothermic operation may be performed by thefeedback controller 1648 applying a forward electric current to thethermoelectric couple array 1643 to induce an exothermic reaction towardthe contact surface 1641. Here, when the feedback controller 1648applies a certain voltage (hereinafter, a voltage causing the exothermicoperation is referred to as a “forward voltage”), to the thermoelectriccouple array 1643, the thermoelectric couple array 1643 initiates theexothermic operation, and the temperature of the contact surface 1641reaches a saturation temperature over time, as shown in FIG. 11.Accordingly, a user feels no sensation or a weak hot sensation at thebeginning of the exothermic operation, feels an increase in hotsensation when the saturation temperature is reached, and then receivesa hot feedback corresponding to the saturation temperature after acertain period of time elapses.

FIG. 12 is a diagram showing an endothermic operation for providing acold feedback according to an embodiment of the present invention, andFIG. 13 is a graph showing the intensity of a cold feedback according toan embodiment of the present invention.

Referring to FIG. 12, the endothermic operation may be performed by thefeedback controller 1648 applying a reverse electric current to thethermoelectric couple array 1643 to induce an endothermic reactiontoward the contact surface 1641. Here, when the feedback controller 1648applies a certain voltage to the thermoelectric couple array 1643(hereinafter, a voltage causing the endothermic operation is referred toas a “reverse voltage”), the thermoelectric couple array 1643 initiatesthe endothermic operation, and the temperature of the contact surface1641 reaches a saturation temperature over time, as shown in FIG. 13.Accordingly, a user feels no sensation or a weak cold sensation at thebeginning of the endothermic operation, feels an increase in coldsensation when the saturation temperature is reached, and then receivesa cold feedback corresponding to the saturation temperature after acertain period of time elapses.

When power is applied to the thermoelectric element, the thermoelectricelement generates heat by converting electric energy into heat energy inaddition to the exothermic reaction and endothermic reaction which aregenerated at both sides of the thermoelectric element. Accordingly, whena voltage with the same magnitude and the opposite current direction isapplied to the thermoelectric couple array 1643, a temperature variationcaused by the exothermic operation may be greater than a temperaturevariation caused by the endothermic operation. Here, the temperaturevariation denotes a difference between an initial temperature and asaturation temperature while the heat output module 1640 is not working.

Hereinafter, the exothermic operation and the endothermic operation,which are performed by a thermoelectric element using electric energy,are collectively referred to as a thermoelectric operation.Additionally, the thermal grill operation, which will be describedbelow, may be interpreted as a kind of “thermoelectric operation”because the thermal grill operation is an operation into which theexothermic operation and the endothermic operation are combined.

2.4.2. Intensity Control for Exothermic/Endothermic Operation

When the heat output module 1640 performs an exothermic operation or anendothermic operation as described above, the feedback controller 1648may control an exothermic level or an endothermic level of the heatoutput module 1640 by adjusting the magnitude of applied voltage.Accordingly, the feedback controller 1648 may adjust the intensity of ahot feedback or a cold feedback by adjusting the magnitude of a voltageas well as by adjusting the direction of current to select the type of aheat feedback to be provided between the hot feedback and the coldfeedback.

FIG. 14 is a graph showing the intensity of a hot/cold feedback usingvoltage adjustment according to an embodiment of the present invention.

For example, as shown in FIG. 14, the feedback device 1600 may providethermal feedbacks with a total of ten intensities (i.e., fiveintensities for the hot feedback and five intensities for the coldfeedback) by the feedback controller 1648 applying voltage magnitudeswith five intensities in a forward or reverse direction.

FIG. 14 shows that the hot feedback has the same number of intensitiesas the cold feedback. However, the number of intensities of the hotfeedback and the number of intensities of the cold feedback do notnecessarily have to be the same and may be different from each other.

Also, it is shown that the hot feedback and the cold feedback areimplemented by changing the current direction while using the samevoltage magnitude. However, the magnitude of the voltage applied for thehot feedback and the magnitude of the voltage applied for the coldfeedback need not be the same.

In particular, when the exothermic operation and the endothermicoperation are performed by applying the same voltage, the temperaturevariation of the hot feedback caused by the exothermic operation isgreater than the temperature variation caused by the endothermicoperation. Thus, by applying a voltage for the cold feedback, which ishigher than the voltage applied for the hot feedback, the sametemperature variation may appear at the same intensity.

The magnitude of the voltage applied to the heat output module 1640,which is controlled in order to control the intensity of the thermalfeedback, has been described above, but the intensity of the thermalfeedback may be controlled in other ways.

As an example, when the thermoelectric couple array 1643 of the heatoutput module 1640 has a plurality of individually controllablethermoelectric couple groups 1644, the feedback controller 1648 maycontrol operation for each thermoelectric couple group 1644 to adjustthe intensity of the thermal feedback.

FIG. 15 is a graph showing adjustment of the intensity of a hot/coldfeedback through operation control for each thermoelectric couple group1644 according to an embodiment of the present invention. Referring toFIG. 15, when the thermoelectric couple array 1643 is composed of fivethermoelectric groups 1644-1, 1644-2, 1644-3, 1644-4, and 1644-5, thefeedback controller 1648 may adjust the intensity of the thermalfeedback by applying a voltage to some or all of the thermoelectriccouple groups 1644. For example, the feedback controller 1648 may applya voltage to all of the thermoelectric couple groups 1644 to provide athermal feedback with the highest intensity to the user, may apply avoltage to only four of the thermoelectric couple groups 1644 to providea thermal feedback with an upper middle intensity, may apply a voltageto only three of the thermoelectric couple groups 1644 to provide athermal feedback with a middle intensity to the user, may apply avoltage to only two of the thermoelectric couple groups 1644 to providea thermal feedback with a lower middle intensity to the user, or mayapply a voltage to only one of the thermoelectric couple groups 1644 toprovide a thermal feedback with the lowest intensity to the user.

When the intensity of the thermal feedback is adjusted depending onwhether to apply a voltage to each of the thermoelectric couple groups1644, the feedback controller 1648 may select a thermoelectric couplegroup 1644 to receive the voltage such that heat distribution is asuniform as possible within allowable limits. To this end, the feedbackcontroller 1648 may determine whether to apply a voltage to thethermoelectric couple groups 1644 by minimizing the number ofconsecutive thermoelectric couple groups 1644 to which the voltage isapplied or the number of consecutive thermoelectric couple groups 1644to which the voltage is not applied. Since the table shown in FIG. 15takes into consideration uniformity of the heat distribution, the abovedescription will be more clearly understood with reference to the abovetable.

As another example, the feedback controller 1648 may adjust theintensity of the thermal feedback by controlling power applicationtiming. In detail, the feedback controller 1648 may adjust the intensityof the thermal feedback by applying power to the thermoelectric couplearrays 1643 using an electric signal in the form of a duty signal with aduty cycle.

FIG. 16 is a graph showing adjustment of the intensity of a hot/coldfeedback through power application timing control according to anembodiment of the present invention. Referring to FIG. 16, it can beseen that the intensity of the thermal feedback is controlled byadjusting the duty rate of the electric signal.

As described above, by adjusting the thermal feedback, it is possible toprovide segmented thermal feedback such as a strong hot sensation, aweak hot sensation, a strong cold sensation, a weak cold sensation, andthe like as well as to just provide a hot sensation and a cold sensationto the user. By using variously segmented thermal feedback, it ispossible to provide a higher degree of immersion to the user under gameenvironments or virtual/augmented reality environments, and it is alsopossible to accurately inspect a patient's sensation when the presentinvention is applied to medical devices.

Also, the intensity of the thermal feedback may be adjusted bycombination of a voltage adjustment scheme, an adjustment scheme foreach thermoelectric couple group 1644 (i.e., a region-based adjustmentscheme), and an adjustment scheme using a duty cycle in addition to theabove-described intensity adjustment method of thermal feedback. Thecombination is obvious to those skilled in the art, and thus a detaileddescription thereof will be omitted.

2.4.2. Thermal Grill Operation

The feedback device 1600 may provide a thermal grill feedback inaddition to the hot feedback and the cold feedback. A thermal painsensation denotes that when a hot spot and a cold spot of a human bodyare simultaneously stimulated, this stimulus is recognized as a painsensation instead of being recognized as a hot sensation and a coldsensation. Accordingly, the feedback device 1600 may provide the headgrill feedback to the user through a thermal grill operation into whichthe exothermic operation and the endothermic operation are combined.

The feedback device 1600 may perform various thermal grill operations toprovide thermal grill feedback. This will be described below after thetypes of thermal grill feedback are described.

2.4.2.1. Types of Thermal Grill Feedback

The thermal grill feedback may include a neutral thermal grill feedback,a hot grill feedback, and a cold grill feedback.

Here, the neutral thermal grill feedback, the hot grill feedback, andthe cold grill feedback cause the user to experience a neutral heatsensation, a hot pain sensation, and a cold pain sensation. The neutralheat pain sensation may refer to only a pain sensation without a hotsensation and a cold sensation, the hot pain sensation may refer to apain sensation in addition to a hot sensation, and the cold painsensation may refer to a pain sensation in addition to a cold sensation.

The neutral heat pain sensation is caused when the intensity of the hotsensation and the intensity of the cold sensation that the user feelscorrespond to predetermined ratio ranges. A ratio at which the userfeels the neutral heat pain sensation (hereinafter referred to as a“neutral ratio”) may be different for each body part that receives athermal feedback, and the neutral ratio may be slightly different foreach individual despite the same human body. In most cases, however, theneutral heat pain sensation tends to be felt while the intensity of thecold sensation is given greater than the intensity of the hot sensation.

Here, the intensity of the thermal feedback may be the amount of heatthat the feedback device 1600 applies to a human body brought intocontact with the contact surface 1641 or the amount of heat that thefeedback device 1600 absorbs from the corresponding human body.Accordingly, when the thermal feedback is applied to a certain area fora certain period of time, the intensity of the thermal feedback may berepresented as a difference between the temperature of the hot sensationor the cold sensation and the temperature of a target portion to whichthe thermal feedback is applied.

On the other hand, human body temperature is usually between 36.5° C.and 36.9° C., and skin temperature is known to be about 30° C. to 32° C.on average but varies for each individual or body part. Palm temperatureis about 33° C., which is slightly higher than the average skintemperature. It will be appreciated that the above-mentioned temperaturevalues may be somewhat different for each individual and may somewhatvary despite the same person.

According to an experiment example, it was confirmed that a neutral heatpain sensation was felt when a hot sensation of about 40° C. and a coldsensation of about 20° C. were applied to a palm of 33° C. Based on thepalm temperature, a hot sensation of about +7° C. and a cold sensationof about −13° C. are applied, and thus the neutral ratio may correspondto 1.86 in terms of temperature.

As can be seen from the above, for most people, the neutral ratio isrepresented as a ratio of a temperature difference caused by the coldsensation to a temperature difference caused by the hot sensation withrespect to a contact target, i.e., a ratio ranges from about 1.5 to 5when the hot sensation and the cold sensation are each continuouslyapplied to a human area of the same size. Also, the hot pain sensationmay be felt when the hot sensation is stronger than the neutral ratio,and the cold pain sensation may be felt when the cold sensation isstronger than the neutral ratio.

2.4.2.2. Thermal Grill Operation According to Voltage Adjustment

The feedback device 1600 may perform a voltage adjustment-based thermalgrill operation. The voltage adjustment-based thermal grill operationmay be applied to the feedback device 1600 with the thermoelectriccouple array 1643 being composed of the plurality of thermoelectriccouple groups 1644.

In detail, the voltage adjustment-based thermal grill operation may beperformed by the feedback controller 1648 applying a forward voltage tosome of the thermoelectric couple groups 1644 to perform an exothermicoperation and applying a reverse voltage to the others to perform anendothermic operation and by the heat output module 1640 providing bothof a hot feedback and a cold feedback.

FIG. 17 is a diagram showing a voltage adjustment-based thermal grilloperation according to an embodiment of the present invention.

Referring to FIG. 17, a thermoelectric couple array 1643 includes aplurality of thermoelectric couple groups 1644 disposed to form aplurality of lines. Here, a feedback controller 1648 may apply power sothat first thermoelectric couple groups 1644-1 (e.g., thermoelectriccouple groups in odd lines) perform an exothermic operation and secondthermoelectric couple groups 1644-2 (e.g., thermoelectric couple groupsin even lines) perform an endothermic operation. By the thermoelectriccouple groups 1644 alternately performing the exothermic operation andthe endothermic operation according to line arrangement as describedabove, the user may simultaneously receive a hot sensation and a coldsensation and thus receive a thermal grill feedback. Here, a distinctionbetween the odd lines and the even lines is arbitrary, and thus theorder of the odd lines and the even lines may be reversed.

Here, the feedback device 1600 may provide a neutral thermal grillfeedback by performing control such that a saturation temperature causedby the exothermic operation of the first thermoelectric couple groups1644-1 and a saturation temperature caused by the endothermic operationof the second thermoelectric couple groups 1644-2 follow the neutralratio.

FIG. 18 is a table regarding a voltage for providing a neutral thermalgrill feedback through voltage adjustment according to an embodiment ofthe present invention.

For example, referring to FIG. 18, a feedback controller 1648 may applyfive forward voltages and five reverse voltages to a heat output module1640, and thus the heat output module 1640 performs the exothermicoperation at five levels and the endothermic operation at five levels.At the same level, a temperature variation caused by the exothermicoperation is the same as that of the endothermic operation. Thefollowing description assumes that the feedback device 1600 has aconstant temperature variation interval of each level. When the neutralratio is set to 3, the feedback controller 1648 may apply a forwardvoltage with the first level, which is the smallest level, to the firstthermoelectric couple groups 1644-1 and apply a reverse voltage with thethird level to the second thermoelectric couple groups 1644-2, and thusthe heat output module 1640 may provide a neutral heat pain sensationfeedback. Similarly, when the neutral ratio is 2.5, the feedbackcontroller 1648 may apply a forward voltage with the second level to thefirst thermoelectric couple groups 1644-1 and apply a reverse voltagewith the fifth level to the second thermoelectric couple groups 1644-2in order to provide a neutral thermal grill feedback. Alternatively,when the neutral ratio is 4, the feedback controller 1648 may apply aforward voltage with the first level to the first thermoelectric couplegroups 1644-1 and apply a reverse voltage with the fourth level to thesecond thermoelectric couple groups 1644-2 to generate a neutral thermalgrill feedback. Alternatively, when the neutral ratio is 2, the feedbackcontroller 1648 may apply either a forward voltage with the first leveland a reverse voltage with the second level or a forward voltage withthe second level and a reverse voltage with the fourth level to providea neutral heat pain sensation. In this case, the former neutral heatpain sensation (when the forward voltage with the first level and thereverse voltage with the second level are used) may be stronger than thelatter neutral heat pain sensation (when the forward voltage with thesecond level and the reverse voltage with the fourth level are used).That is, even for the thermal grill feedback, the intensity of thethermal grill feedback may be adjusted. On the other hand, the abovedescription regarding the method of providing the neutral heat painsensation is illustrative, and thus the present invention is not limitedthereto. For example, it is not necessary for the number of levels ofthe thermal feedback to be five, and the number of levels of the coldfeedback may be different from that of the hot feedback. Also, it is notnecessary that the temperature variation interval of each level shouldbe constant, and for example, a voltage interval of each level may beconstant.

Also, the feedback controller 1648 may provide a hot grill feedback byadjusting the forward voltage and the reverse voltage to be equal to orless than the neutral ratio and may provide a cold grill feedback byadjusting the forward voltage and the reverse voltage to be equal to orgreater than the neutral ratio.

For example, referring to FIG. 18 again, when the neutral ratio is setto 3, the feedback controller 1648 may apply a forward voltage with thefirst level to the first thermoelectric couple groups 1644-1 and apply areverse voltage with the first level or the second level to the secondthermoelectric couple groups 1644-2. Then, the heat output module 1640may generate a heat sensation and a pain sensation at a ratio lower thanthe neutral ratio and thus may provide a hot grill feedback to enable auser to simultaneously feel a hot sensation and a pain sensation. Inthis case, the forward voltage need not necessarily be the forwardvoltage used for the neutral thermal grill feedback. In other words, thefeedback controller 1648 may allow the heat output module 1640 toprovide a hot grill feedback using a forward voltage with the fourthlevel and a reverse voltage with the fourth level.

For the cold grill feedback, when the neutral ratio is set to 3, thefeedback controller 1648 may apply either a forward voltage with thefirst level and a reverse voltage with the fourth level or a forwardvoltage with the first level and a reverse voltage with the fifth levelto the heat output module 1640.

However, when the hot grill feedback or the cold grill feedback isintended to be provided and the forward voltage and the reverse voltageare applied at a ratio significantly different from the neutral ratio,the user may not feel a pain sensation. Thus, it may be preferable thatthe levels of the forward voltage/the reverse voltage be adjusted suchthat the ratio becomes close to the neutral ratio.

2.5. Heat Transfer Operation

The heat transfer operation will be described below. Here, the heattransfer operation is an operation of transferring heat in an area ofthe heat output module and may be performed using a heat output module1640 composed of a plurality of individually controllable thermoelectriccouple groups 1644.

FIG. 19 is a schematic diagram showing an example electric signal for aheat transfer operation according to an embodiment of the presentinvention, and FIG. 20 is a diagram showing the heat transfer operationof FIG. 19.

Referring to FIGS. 19 and 20, the heat output module 1640 may include afirst thermoelectric couple group 1644-1, a second thermoelectric couplegroup 1644-2, a third thermoelectric couple group 1644-3, and a fourththermoelectric couple group 1644-4.

In this case, the feedback controller 1648 may sequentially apply powerto the thermoelectric element groups. Accordingly, first, the firstthermoelectric couple group may perform a thermoelectric operation(here, the thermoelectric operation includes the exothermic operation,the endothermic operation, and the thermal grill operation).Subsequently, the thermoelectric operation may be performed in the orderof the second, third, and fourth thermoelectric couple groups 1644-2,1644-3, and 1644-4.

Also, when powering on a specific thermoelectric couple group 1644, thefeedback controller 1648 may power off a previous thermoelectric couplegroup 1644. Thus, the first thermoelectric couple group 1644-1 may stopthe thermoelectric operation when the second thermoelectric couple group1644-2 initiates the thermoelectric operation, the second thermoelectriccouple group 1644-2 may stop the thermoelectric operation when the thirdthermoelectric couple group 1644-3 initiates the thermoelectricoperation, and the third thermoelectric couple group 1644-3 may stop thethermoelectric operation when the fourth thermoelectric couple group1644-4 initiates the thermoelectric operation.

Thus, a user may feel a transfer of heat from a region where the firstthermoelectric couple group 1644-1 is disposed on a contact surface to aregion where the fourth thermoelectric couple group 1644-4 is disposedon the contact surface.

The aforementioned example may be utilized as follows.

For example, when a plurality of thermoelectric element groups arehorizontally arranged in the feedback device while being gripped by auser, the user may be provided with a feeling that a cool wind ispassing by transferring cold heat from one side to another. Also, a usermay be provided with a feeling that a heat source is passing bytransferring hot heat.

FIG. 21 is a schematic diagram showing another example electric signalfor a heat transfer operation according to an embodiment of the presentinvention, and FIG. 22 is a diagram showing the heat transfer operationof FIG. 21.

Referring to FIGS. 21 and 22, the heat output module 1640 may include afirst thermoelectric couple group 1644-1, a second thermoelectric couplegroup 1644-2, a third thermoelectric couple group 1644-3, and a fourththermoelectric couple group 1644-4.

In this case, the feedback controller 1648 may sequentially apply powerto the thermoelectric couple groups 1644. Accordingly, first, the firstthermoelectric couple group 1644-1 may perform the thermoelectricoperation. Subsequently, the thermoelectric operation may be performedin the order of the second, third, and fourth thermoelectric couplegroups 1644-2, 1644-3, and 1644-4.

Also, at a predetermined time after powering on a specificthermoelectric couple group 1644, the feedback controller 1648 may poweroff a previous thermoelectric couple group. Thus, a user may sense athermal sensation caused by the second thermoelectric couple group1644-2 when the thermal sensing caused by the first thermoelectriccouple group 1644-1 ends, may sense a thermal sensation caused by thethird thermoelectric couple group 1644-3 when the thermal sensing causedby the second thermoelectric couple group 1644-1 ends, and may sense athermal sensation caused by the fourth thermoelectric couple group1644-4 when the thermal sensing caused by the third thermoelectriccouple group 1644-3 ends.

This takes into consideration that a predetermined time is requireduntil the contact surface reaches a temperature at which the user feel ahot sensation after power is applied to the thermoelectric couple group.That is, the predetermined time may correspond to a delay time requireduntil the temperature of the contact surface reaches a temperaturesuitable for transferring a hot sensation after power is applied to thethermoelectric element.

Thus, a user may naturally feel a transfer of heat from a region wherethe first thermoelectric couple group 1644-1 is disposed on the contactsurface to a region where the fourth thermoelectric couple group 1644-4is disposed on the contact surface.

FIG. 23 is a schematic diagram showing still another example electricsignal for a heat transfer operation according to an embodiment of thepresent invention, and FIG. 24 is a diagram showing the heat transferoperation according to an embodiment of the present invention.

Referring to FIGS. 23 and 24, the heat output module 1640 may include afirst thermoelectric couple group 1644-1, a second thermoelectric couplegroup 1644-2, a third thermoelectric couple group 1644-3, and a fourththermoelectric couple group 1644-4.

In this case, the feedback controller 1648 may sequentially apply powerto the thermoelectric couple groups 1644. Accordingly, first, the firstthermoelectric couple group 1644-1 may perform the thermoelectricoperation. Subsequently, the thermoelectric operation may be performedin the order of the second, third, and fourth thermoelectric couplegroups 1644-2, 1644-3, and 1644-4.

Also, the feedback controller 1648 may not power off a thermoelectricelement which is already powered on. Thus, a user may feel a transfer ofheat from a region where the first thermoelectric couple group 1644-1 isdisposed on the contact surface to a region where the fourththermoelectric couple group 1644-4 is disposed on the contact surface.

The aforementioned example may be utilized as follows.

For example, when a plurality of thermoelectric couple groups 1644 arevertically arranged in the feedback device while being gripped by auser, the user may be provided with a feeling that he or she is immersedin cold water starting from the bottom of the body by transferring coldheat from a lower side to an upper side.

FIG. 25 is a schematic diagram showing still another example electricsignal for the heat transfer operation according to an embodiment of thepresent invention, and FIG. 26 is a diagram showing the heat transferoperation of FIG. 25.

Referring to FIGS. 25 and 26, the heat output module 1640 may include afirst thermoelectric couple group 1644-1, a second thermoelectric couplegroup 1644-2, a third thermoelectric couple group 1644-3, and a fourththermoelectric couple group 1644-4.

In this case, all the thermoelectric couple groups are powered on toperform the thermoelectric operation.

In this case, the feedback controller 1648 may sequentially power offthe thermoelectric couple groups 1644. Accordingly, first, the firstthermoelectric couple group 1644-1 may stop the thermoelectricoperation. Subsequently, the thermoelectric operation may be stopped inthe order of the second, third, and fourth thermoelectric couple groups1644-2, 1644-3, and 1644-4.

Thus, a user may feel a transfer of heat from a region where the firstthermoelectric couple group 1644-1 is disposed on the contact surface toa region where the fourth thermoelectric couple group 1644-4 is disposedon the contact surface.

The aforementioned example may be utilized as follows.

For example, when a plurality of thermoelectric couple groups 1644 arevertically arranged in the feedback device while being gripped by auser, the user may be provided with a feeling that he or she isseparated from cold water starting from the bottom of the body bytransferring cold heat from a lower side to an upper side.

In the above-described example of the heat transfer operation, the fourthermoelectric couple groups 1644 have been described as being arrangedin a one-dimensional array. However, the number and arrangement ofthermoelectric couple groups 1644 in the heat transfer operationaccording to an embodiment of the present invention are not limited tothe above example.

3. Thermal Feedback Recognition Enhancement Method

A thermal feedback recognition enhancement method according to anembodiment of the present invention will be described below. Here, thethermal feedback recognition enhancement method may be understood as anoperation for a user enhancing a thermal sensation degree according to athermal feedback when the feedback device 1600 outputs the feedback.

As described above, a heat transfer operation may be performed in thefeedback device 1600.

As shown in the example of FIG. 19, the feedback controller 1648 maysequentially power on thermoelectric element groups and may output athermal feedback in the order of the first to fourth thermoelectriccouple groups 1644-1 to 1644-4. Thus, a user may feel a transfer of heatfrom a region where the first thermoelectric couple group 1644-1 isdisposed on the contact surface to a region where the fourththermoelectric couple group 1644-4 is disposed on the contact surface.However, although a thermal feedback output from the firstthermoelectric couple group 1644-1 has the same intensity as a thermalfeedback output from the second thermoelectric couple group 1644-4, auser may feel that the intensity of the first thermoelectric couplegroup 1644-1 is different from the intensity of the fourththermoelectric couple group 1644-4.

For example, a user may feel that a sensible temperature correspondingto the thermal feedback output from the first thermoelectric couplegroup 1644-1 is different from a sensible temperature corresponding tothe thermal feedback output from the second thermoelectric couple group1644-2. This is because a human body part that senses the thermalfeedback output from the second thermoelectric couple group 1644-2 maybe affected by the thermal feedback output from the first thermoelectriccouple group 1644-1.

As a specific example, the content reproduction device 1200 outputs hotfeedback data including a command to instruct to output a hot feedbackat a specific time according to reproduction of a specific portion ofcontent, and the feedback device 1600 may apply a voltage for outputtingthe hot feedback to the first thermoelectric couple group 1644-1 and thesecond thermoelectric couple group 1644-2 at the specific time point.However, even when the thermal feedback output by the firstthermoelectric couple group 1644-1 and the thermal feedback output bythe second thermoelectric couple group 1644-2 have a sensibletemperature of T degrees, heat sensing organs distributed in the bodypart that senses the thermal feedback output from the secondthermoelectric couple group 1644-2 are distributed by the thermalfeedback output from the first thermoelectric couple group 1644-1, andthus the human part may sense the thermal feedback output from thesecond thermoelectric couple group 1644-1 at a temperature of higherthan T degrees. Thus, a time point at which the user senses the thermalfeedback output from the second thermoelectric couple group 1644-2 isalso delayed. As a result, the user cannot sense a thermal experiencewhen the specific portion of the content is reproduced.

However, in this case, by the feedback device 1600 performing thethermal feedback recognition enhancement method, the user may sense athermal sensation at a time intended by the content reproduction device1200 when the intensity or temperature of the thermal feedback outputfrom the second thermoelectric couple group 1644-2 is distinguished inconsideration of the thermal feedback output from the firstthermoelectric couple group 1644-1, in the above example, when thesecond thermoelectric couple group 1644-2 outputs a thermal feedbackhaving a temperature exceeding T degrees at the specific time point.

Accordingly, in order to solve such a problem, a thermal feedbackrecognition enhancement method for enhancing a user's cognition of athermal feedback will be described below. Also, for convenience ofdescription, the following description assumes that the thermal feedbackrecognition enhancement method is performed by the feedback device 1600.However, the present invention is not limited thereto, and the thermalfeedback recognition enhancement method may be performed by the contentreproduction device 1200 and may be performed by a third apparatus otherthan the feedback device 1600 and the content reproduction device 1200.

3.1. Overshoot of Thermal Feedback

As described above, when thermal feedbacks are output by a plurality ofthermoelectric couple groups 1644 according to the heat transferoperation, a user's cognition of thermal feedback output by thesubsequent thermoelectric couple group may be lowered due to the thermalfeedback output from the previous thermoelectric couple group.

According to the present invention, in order to enhance the recognitionof the thermal feedback output from the subsequent thermoelectric couplegroup of the user, an overshoot may be generated in the thermal feedbackoutput from the subsequent thermoelectric couple group as the thermalfeedback recognition enhancement method. Here, an overshoot may denotethat when a thermal feedback of a specific intensity should be outputfrom a thermoelectric couple group, the temperature of thethermoelectric couple group exceeds a saturation temperaturecorresponding to the specific intensity before the temperature of thethermoelectric couple group reaches the saturation temperature.

In detail, FIG. 27 is a diagram illustrating a change in applied voltagefor generating an overshoot of a thermal feedback and a change intemperature with respect to the overshoot according to an embodiment ofthe present invention.

Referring to FIG. 27, the thermoelectric couple array 1643 or thecontact surface 1641 has a predetermined heat capacity. Thus, when anexothermic operation or endothermic operation is initiated by applyingoperating power to a thermoelectric couple group in order to output athermal feedback, the temperature of the contact surface 1641 graduallychanges from an initial temperature and reaches the saturationtemperature instead of reaching the saturation temperature as soon aspower is applied. For example, when operating power (a first forwardvoltage in the example of FIG. 27) is applied to a thermoelectric couplegroup at a first time point in order to output a hot feedback with afirst intensity, the temperature of the contact surface 1641 graduallyincreases from an initial temperature and reaches a first saturationtemperature along a first reference temperature curve 2710. Also, whensecond forward voltage is applied to the thermoelectric couple group atthe first time point in order to output a hot feedback with a secondintensity, the temperature of the contact surface 1641 reaches a secondsaturation temperature along a second reference temperature curve 2720.

According to an embodiment of the present invention, in order to enhancerecognition of a user's hot feedback, the feedback device 1600 maygenerate an overshoot for the hot feedback. For example, when the hotfeedback with the first intensity is output, the feedback device 1600may apply excessive power (a second forward voltage in the example ofFIG. 27), which is higher than the operating power (i.e., the firstforward voltage) for outputting the hot feedback with the firstintensity, to the thermoelectric couple group from the first time to thesecond time point for overshoot generation. Here, the excessive powermay refer to power applied to generate the overshoot (hereinafter thevoltage and current of the excessive power are referred to as an“excessive voltage” and an “excessive current”). In this case, theexcessive power may be in the same direction as the operating power.That is, the excessive power may be a forward voltage when the operatingpower is a forward voltage, and the excessive power may be a reversevoltage when the operating power is a reverse voltage.

When the excessive power is applied, the temperature of the contactsurface 1641 may increase, not along the first reference temperaturecurve 2710, but along the second reference temperature curve 2720. Inthis case, the temperature of the contact surface 1641 may be higherthan the first saturation temperature at the second time point. Also,the feedback device 1600 may apply operating power for the hot feedbackwith the first intensity at the second time point. Accordingly, thetemperature of the contact surface 1641 may gradually decrease from thetemperature of the contact surface 1641 at the second time point toreach the first saturation temperature. That is, the temperature of thecontact surface 1641 at the second time point may be a thresholdtemperature.

In summary, when the hot feedback with the first intensity, which is atarget intensity, is output and the excessive power, which is greaterthan the operating power, is applied to a thermoelectric couple group atthe first time, the temperature of the contact surface 1641 at thesecond time point may be higher than the first saturation temperaturecorresponding to the first intensity. Also, when the operating power isapplied to the thermoelectric couple group at the second time point, thetemperature of the contact surface 1641 may be lowered from thethreshold temperature, which is the temperature of the contact surface1641 at the second time point, to the first saturation temperature.Accordingly, a user may temporarily feel the threshold temperature,which is higher than the first saturation temperature. Thus, the usermay more clearly feel the hot feedback, and also the user may moreearlier recognizes the hot feedback with the first intensity.

According to an embodiment of the present invention, the magnitude ofthe excessive voltage (a second forward voltage in the example of FIG.27) applied for the overshoot may be predetermined. For example, asshown in the example of FIG. 27, the excessive voltage may be a voltagethat is one step higher than the operating voltage (a first forwardvoltage in the example of FIG. 27) indicating a voltage with an intendedintensity, that is, a voltage of the target intensity and may be avoltage that is multiple steps higher than the operating voltage. Also,the excessive voltage may be predetermined irrespective of the intensityof the thermal feedback. For example, the excessive voltage may behigher than the operating voltage by a predetermined value. Also, theratio of the operating voltage to the excessive voltage may bepredetermined.

In addition, as the excessive voltage is predetermined, a temperature (asecond saturation temperature in the example of FIG. 27) correspondingto the excessive voltage may also be predetermined.

Likewise, the temperature corresponding to the excessive voltage may bea temperature that is determined to output a thermal feedback with apredetermined intensity and may be a temperature that is not related tothe thermal feedback with the predetermined intensity. Also, thetemperature corresponding to the excessive voltage may be higher thanthe saturation temperature corresponding to the operating voltage by apredetermined value, and the ratio of the temperature corresponding tothe excessive voltage to the saturation temperature corresponding to theoperating voltage may be predetermined.

Also, according to an embodiment of the present invention, a time pointat which the application of the excessive voltage is stopped, that is, atime point at which the operating voltage is applied, may bepredetermined. According to an embodiment of the present invention, thetime point at which the application of the excessive voltage is stoppedmay be determined depending on the threshold temperature. That is, thetime point at which the application of the excessive voltage is stoppedaffects the threshold temperature, and thus the time point at which theapplication of the excessive voltage is stopped may be predetermined inconsideration of a relation between the threshold temperature and thetime point at which the application of the excessive voltage is stopped.For example, the feedback device 1600 may stop applying the excessivevoltage when the temperature of the contact surface 1641 reaches apredetermined threshold temperature. According to another embodiment ofthe present invention, the time point at which the application of theexcessive voltage is stopped may be determined on the basis of thetarget intensity. For example, the time point at which the applicationof the excessive voltage is stopped may be t seconds when the targetintensity is the first intensity and may be t+a seconds (or t−a seconds)when the target intensity is the second intensity.

FIG. 28 is a diagram illustrating a change in applied voltage forgenerating an overshoot of a thermal feedback and a change intemperature with respect to the overshoot according to anotherembodiment of the present invention.

Referring to FIG. 28, when an operating voltage (a first forward voltagein the example of FIG. 28) is applied to the thermoelectric couple group1644 at the first time point in order to output a hot feedback of atarget intensity, the temperature of the contact surface 1641 mayincrease along a first reference curve 2810 to reach the firstsaturation temperature. In this case, when a first overshoot (a secondforward voltage in the example of FIG. 28) is applied between the firsttime point and the second time point for overshoot generation, thetemperature of the contact surface 1641 may increase between the firsttime point and the second time point along a second referencetemperature curve 2820, and thus the temperature of the contact surface1641 may reach a first threshold temperature which is higher than thefirst saturation temperature at the second time point. A user mayrecognize the hot feedback more clearly when the temperature of thecontact surface 1641 reaches the first threshold temperature than whenthe operating voltage is applied from the first time point.

Also, according to an embodiment of the present invention, the feedbackdevice 1600 may apply a second overshoot (a third forward voltage in theexample of FIG. 28), which is higher than the first overshoot, betweenthe first time point and the second time point. In this case, as thetemperature of the contact surface 1641 increases between the first timepoint and the second time point along a third reference temperaturecurve 2830, the temperature of the contact surface 1641 at the secondtime point may reach a second threshold temperature which is higher thanthe first threshold temperature. The temperature of the contact surface1641 at the second time point may further increase when the secondovershoot is applied between the first time point and the second timepoint than when the first overshoot is applied between the first timepoint and the second time point. Thus, a user may clearly feel the hotfeedback, and a time point at which the user recognizes the hot feedbackmay become earlier than when the first overshoot is applied.

FIG. 29 is a diagram illustrating a change in applied voltage forgenerating an overshoot of a thermal feedback and a change intemperature with respect to the overshoot according to still anotherembodiment of the present invention.

Referring to FIG. 29, when an operating voltage (a first forward voltagein the example of FIG. 29) is applied to the thermoelectric couple group1644 at the first time point in order to output a hot feedback of atarget intensity, the temperature of the contact surface 1641 mayincrease along a first reference curve 2910 to reach a first saturationtemperature. In this case, when an overshoot (a second forward voltagein the example of FIG. 29) is applied between the first time point andthe second time point for overshoot generation, the temperature of thecontact surface 1641 may increase between the first time point and thesecond time point along a second reference temperature curve 2920, andthus the temperature of the contact surface 1641 may reach a firstthreshold temperature, which is higher than the first saturationtemperature, at the second time point. A user may better recognize thehot feedback when the temperature of the contact surface 1641 reachesthe first threshold temperature than when the operating voltage isapplied from the first time point.

Also, according to an embodiment of the present invention, the feedbackdevice 1600 may apply the excessive voltage from the first time pointand up to a third time point which is after the second time point. Inthis case, as the temperature of the contact surface 1641 increases upto the third time point along the second reference temperature curve2920, the temperature of the contact surface 1641 at the third timepoint may reach a second threshold temperature higher than the firstthreshold temperature, which is the temperature of the contact surface1641 at the second time point. Thus, a user may feel the hot feedbackmore clearly than when the excessive voltage is applied up to the secondtime point.

FIG. 30 is a diagram illustrating a change in applied voltage forgenerating an overshoot of a cold feedback and a change in temperaturewith respect to the overshoot according to an embodiment of the presentinvention.

Referring to FIG. 30, even in the case where the cold feedback isoutput, as in the case where the hot feedback is output, when theendothermic operation is initiated, the temperature of the contactsurface 1641 gradually changes from an initial temperature and reachesthe saturation temperature instead of reaching the saturationtemperature as soon as power is applied

When an operating voltage (a first reverse voltage in the example ofFIG. 30) is applied to a thermoelectric couple group at a first timepoint in order to output a cold feedback with a first intensity, thetemperature of the contact surface 1641 gradually decreases from aninitial temperature and reaches a first-prime saturation temperaturealong a first reference temperature curve 3010. Also, when an overshoot(a second reverse voltage in the example of FIG. 30) is applied to athermoelectric couple group at the first time point in order to output acold feedback with a second intensity, the temperature of the contactsurface 1641 reaches a second-prime saturation temperature along asecond reference temperature curve 3020.

According to an embodiment of the present invention, in order to enhancerecognition of a user's cold feedback, the feedback device 1600 maygenerate an overshoot for the cold feedback. For example, when the coldfeedback with the first intensity is output, the feedback device 1600may apply an excessive voltage, which is higher than an operatingvoltage for the cold feedback with the first intensity, to thethermoelectric couple group from the first time point to the second timepoint for overshoot generation. When the excessive voltage is applied,the temperature of the contact surface 1641 may decrease, not along thefirst reference temperature curve 3010, but along the second referencetemperature curve 3020. In this case, the temperature of the contactsurface 1641 may be lower than the first-prime saturation temperature atthe second time point. Also, the feedback device 1600 may apply theoperating voltage for the cold feedback with the first intensity at thesecond time point. Accordingly, the temperature of the contact surface1641 may gradually increase from the temperature of the contact surface1641 at the second time point to reach the first-prime saturationtemperature. That is, the temperature of the contact surface 1641 at thesecond time point may be a threshold temperature.

According to an embodiment of the present invention, the magnitude ofthe excessive voltage applied for the overshoot may be predetermined,and also the temperature corresponding to the voltage applied for theovershoot may be predetermined. Also, a time point at which theapplication of the voltage applied for the overshoot is stopped, thatis, a time point at which the operating voltage is applied, may bepredetermined.

Also, according to an embodiment of the present invention, a voltagehigher than the excessive voltage may be applied at the second timepoint in order to generate the overshoot. The description with referenceto FIGS. 27 to 29 may be applied to various implementations as it is,and thus a detailed description thereof will be omitted.

3.2. Implementation of Thermal Feedback Recognition Enhancement Method

FIG. 31 is a flowchart showing a thermal feedback recognitionenhancement method according to an embodiment of the present invention.

The recognition enhancement method according to FIG. 31 may includechecking the types and intensities of thermal feedbacks output from afirst thermoelectric couple group and a second thermoelectric couplegroup (S3110) and applying, to the second thermoelectric couple group,cognitive enhancing power that is the same as, or different from,operating power that is predetermined by the types and intensities ofthe thermal feedbacks (S3120).

In the recognition enhancement method according to an embodiment of thepresent invention, each of the first thermoelectric couple group and thesecond thermoelectric couple group may indicate a group ofthermoelectric elements that are individually controlled, and the firstthermoelectric couple group and the second thermoelectric couple groupmay be adjacent in distance. As an example, the first thermoelectriccouple group and the second thermoelectric couple group may be includedin the same thermoelectric couple group.

In detail, the feedback device 1600 may check the types and intensitiesof the thermal feedbacks output from the first thermoelectric couplegroup and the second thermoelectric couple group (S3110). In this case,the types and intensities of the thermal feedbacks output from the firstthermoelectric couple group and the second thermoelectric couple groupmay be the same as or different from each other. Also, the types(forward voltage/reverse voltage) and magnitudes of voltages applied tothe first thermoelectric couple group and the second thermoelectriccouple group may be predetermined according to the types and intensitiesof the thermal feedbacks. Also, operating power applied to the firstthermoelectric couple group and the second thermoelectric couple groupto output the thermal feedbacks may be predetermined according to thetypes and intensities of the thermal feedbacks.

According to an embodiment of the present invention, the feedback device1600 may acquire thermal feedback data from the content reproductiondevice 1200. The thermal feedback data may include information regardingthe types and intensities of thermal feedbacks output fromthermoelectric couple groups and the output start times and/or end timesof the thermal feedbacks. The feedback device 1600 may check the typesand intensities of the thermal feedbacks output from the thermoelectriccouple groups on the basis of the thermal feedback data.

Also, the time point at which the thermal feedback is output from thefirst thermoelectric couple group may be different from the time pointat which the thermal feedback is output from the second thermoelectriccouple group. For example, according to the above heat transferoperation, the thermal feedback may be output from the secondthermoelectric couple group after the thermal feedback is output fromthe first thermoelectric couple group. It will be appreciated that, asshown in FIGS. 19 to 26, the time points at which the thermal feedbacksare output from the first thermoelectric couple group and the secondthermoelectric couple group may differ depending on the embodiment.

Also, the feedback device 1600 may apply, to the second thermoelectriccouple group, cognitive enhancing power that is the same as, ordifferent from, operating power that is predetermined by the type andintensity of the thermal feedback output from the second thermoelectriccouple group.

Here, cognitive enhancing power may refer to power applied to athermoelectric couple group in order to enhance a user's cognition of athermal feedback. For example, the cognitive enhancing power may includethe aforementioned excessive power. Also, the cognitive enhancing powermay include a variety of power for enhancing a user's cognition althoughan overshoot is not generated like the aforementioned excessive power.

As described above, due to the thermal feedback output from the firstthermoelectric couple group, the user may not recognize the thermalfeedback output from the second thermoelectric couple group at anintended intensity at a time intended by the feedback device 1600. Thus,in order to enhance the user's cognition of the thermal feedback, thefeedback device 1600 may adjust the thermal feedback output from thesecond thermoelectric couple group. To this end, the feedback device1600 may apply, to the second thermoelectric couple group, a voltagedifferent from a voltage predetermined by the type and intensity of thethermal feedback. However, the magnitude, application time, etc. of thevoltage applied to the second thermoelectric couple group in order toenhance the recognition of the thermal feedback may differ depending onvarious situations, for example, the types and intensities of thethermal feedbacks output from the first thermoelectric couple group andthe second thermoelectric couple group. For example, in order to enhancethe recognition of the thermal feedback, the feedback device 1600 mayapply, to the second thermoelectric couple group, a voltage that is thesame as the voltage predetermined by the type and intensity of thethermal feedback.

Implementations of the thermal feedback recognition enhancement methodin various situations will be described below. Also, for convenience ofdescription, the following description focuses on a case in which hotfeedbacks are to be output from the first and second thermoelectriccouple groups. However, the present invention is not limited thereto,and it will be appreciated that the following description may be appliedto cases in which cold feedbacks or thermal grill feedbacks are to beoutput by the first and second thermoelectric couple groups.

FIG. 32 is a diagram showing a change in temperature on a contactsurface and a change in applied voltage according to a thermal feedbackrecognition enhancement method when thermal feedbacks with the sameintensity are output from a first thermoelectric couple group and asecond thermoelectric couple group according to an embodiment of thepresent invention.

Referring to FIG. 32, the first thermoelectric couple group and thesecond thermoelectric couple group may simultaneously output a hotfeedback with a first intensity. However, according to the heat transferoperation, the hot feedback may be output from the second thermoelectriccouple group after the hot feedback is output from the firstthermoelectric couple group.

In detail, at a first time point, a first operating voltage (a firstforward voltage in the example of FIG. 32) for outputting the hotfeedback with the first intensity may be applied to the firstthermoelectric couple group. Thus, the temperature of the contactsurface of the first thermoelectric couple group may rise up to a firstsaturation temperature. As an example, the first thermoelectric couplegroup may be a thermoelectric couple group in the thermoelectric couplearray in which the heat transfer operation is performed firstly. From asecond time point, which is a predetermined time after the first timepoint, to a third time point, an excessive voltage (a second forwardvoltage in the example of FIG. 32) higher than a second operatingvoltage (a first forward voltage in the example of FIG. 32) foroutputting the hot feedback with the first intensity may be applied tothe second thermoelectric couple group. For example, the excessivevoltage may be a voltage for outputting a hot feedback with a secondintensity. As the excessive voltage is applied from the second timepoint to the third time point, the temperature of the contact surface ofthe second thermoelectric couple group may rise along a second referencetemperature curve 3220, and the temperature of the contact surface ofthe second thermoelectric couple group at the third time point, that is,a threshold temperature may be higher than a first saturationtemperature. As the threshold temperature increases over the firstsaturation temperature, it is possible to enhance recognition of athermal feedback output from the second thermoelectric couple group.

FIG. 33 is a diagram showing a change in temperature on a contactsurface and a change in applied voltage according to a thermal feedbackrecognition enhancement method when thermal feedbacks with the sameintensity are output from the first thermoelectric couple group and thesecond thermoelectric couple group according to another embodiment ofthe present invention.

Referring to FIG. 33, the first thermoelectric couple group and thesecond thermoelectric couple group may simultaneously output a hotfeedback with a first intensity. However, according to the heat transferoperation, the hot feedback may be output from the second thermoelectriccouple group after the hot feedback is output from the firstthermoelectric couple group.

Compared to FIG. 33, the feedback device 1600 may perform the thermalfeedback recognition enhancement method even on the first thermoelectriccouple group. For example, according to the heat transfer operation,another thermoelectric couple group adjacent to the first thermoelectriccouple group may output a thermal feedback earlier than the firstthermoelectric couple group, and the user's cognition of the thermalfeedback output from the first thermoelectric couple group may belowered due to the thermal feedback output from the other thermoelectriccouple group. Thus, according to the present invention, the thermalfeedback recognition enhancement method may be performed even on thefirst thermoelectric couple group. Also, even when the thermal feedbackis not output from the other thermoelectric couple group, an overshootmay be generated for the thermal feedback of the first thermoelectriccouple group in order to enhance the user's cognition of the thermalfeedback output from the first thermoelectric couple group irrespectiveof whether a nearby thermoelectric couple group outputs a thermalfeedback.

As the thermal feedback recognition enhancement method is performed onthe first thermoelectric couple group, an excessive voltage (a secondforward voltage in the example of FIG. 33) higher than the operatingvoltage (a first forward voltage in the example of FIG. 33) foroutputting the hot feedback with the first intensity may be applied tothe first thermoelectric couple group between the first time point andthe second time point. Thus, by the temperature of the contact surfaceof the first thermoelectric couple group increasing along a secondreference temperature curve 3320, the temperature of the contact surfaceof the first thermoelectric couple group at the second time point may behigher than the first saturation temperature. That is, an overshootinterval indicating a time interval in which the temperature of thecontact surface of the first thermoelectric couple group is higher thanthe first saturation temperature may occur. Subsequently, the operatingvoltage is applied to the first thermoelectric couple group at thesecond time point so that the temperature of the contact surface of thefirst thermoelectric couple group may drop to the first saturationtemperature.

Likewise, the thermal feedback recognition enhancement method may beperformed even on the second thermoelectric couple group.

FIG. 34 is a diagram showing a change in temperature on a contactsurface according to a thermal feedback recognition enhancement methodwhen a thermal feedback with a higher intensity is output from thesecond thermoelectric couple group than from the first thermoelectriccouple group according to an embodiment of the present invention.

Referring to FIG. 34, in portions FIG. 34A and FIG. 34B, a thermalfeedback with a higher intensity may be output from the secondthermoelectric couple group than from the first thermoelectric couplegroup. As an example, a hot feedback with a first intensity may beoutput from the first thermoelectric couple group, and a hot feedbackwith a second intensity higher than the first intensity may be outputfrom the second thermoelectric couple group. Also, according to the heattransfer operation, the hot feedback may be output from the secondthermoelectric couple group after the output of the hot feedback fromthe first thermoelectric couple group is initiated.

Referring to FIG. 34A, the feedback device 1600 may generate anovershoot for the hot feedback with the second intensity output from thesecond thermoelectric couple group, as in the case where the hotfeedback with the same intensity is output from the first thermoelectriccouple group and the second thermoelectric couple group. For example, anexcessive voltage (a third forward voltage in the example of FIG. 34)higher than an operating voltage (a second forward voltage in theexample of FIG. 34) for the hot feedback with the second intensity maybe applied to the second thermoelectric couple group from a second timepoint, which is after the first time point at which the hot feedbackwith the first intensity is output from the first thermoelectric couplegroup, to a third time point. Thus, the temperature of the contactsurface of the second thermoelectric couple group may increase along athird reference temperature curve 3430 from the second time point to thethird time point, and the temperature of the contact surface of thesecond thermoelectric couple group at the third time point may be higherthan the second saturation temperature. Subsequently, the operatingvoltage for the hot feedback with the second intensity is applied at thethird time point so that the temperature of the contact surface of thesecond thermoelectric couple group may reach the second saturationtemperature. Thus, an overshoot of the hot feedback output from thesecond thermoelectric couple group may be generated while thetemperature of the contact surface of the second thermoelectric couplegroup is higher than the second saturation temperature (i.e., during atime interval between a third-prime time point and a third-double-primetime point). As the overshoot is generated, it is possible to enhancerecognition of the thermal feedback output from the secondthermoelectric couple group.

Referring to FIG. 34B, unlike FIG. 34A, the feedback device 1600 may notgenerate an overshoot for the hot feedback output from the secondthermoelectric couple group. In detail, the hot feedback with the secondintensity, which is higher than the hot feedback with the firstintensity output from the first thermoelectric couple group, is outputfrom the second thermoelectric couple group. In this case, thetemperature of the contact surface of the second thermoelectric couplegroup is higher than the first saturation temperature, which is thetemperature of the contact surface of the first thermoelectric couplegroup. Thus, although a user's senses are disturbed by the hot feedbackof the first thermoelectric couple group, the user is not affected bythe hot feedback of the first thermoelectric couple group and mayrecognize the hot feedback output from the second thermoelectric couplegroup. Accordingly, when the feedback device 1600 confirms that theintensity of the thermal feedback output from the second thermoelectriccouple group is higher than the intensity of the thermal feedback outputfrom the first thermoelectric couple group, the feedback device 1600does not generate an overshoot for the thermal feedback of the secondthermoelectric couple group and may output the thermal feedback with theconfirmed intensity.

FIG. 35 is a diagram showing a change in temperature on a contactsurface according to a thermal feedback recognition enhancement methodwhen a thermal feedback with a lower intensity is output from the secondthermoelectric couple group than from the first thermoelectric couplegroup according to an embodiment of the present invention.

Referring to FIG. 35, in portions FIG. 35A, FIG. 35B, and FIG. 35C, athermal feedback with a lower intensity may be output from the secondthermoelectric couple group than from the first thermoelectric couplegroup. As an example, a hot feedback with a second intensity may beoutput from the first thermoelectric couple group, and a hot feedbackwith a first intensity lower than the second intensity may be outputfrom the second thermoelectric couple group. Also, according to the heattransfer operation, the hot feedback may be output from the secondthermoelectric couple group after the output of the hot feedback fromthe first thermoelectric couple group is initiated.

Referring to FIG. 35A, the feedback device 1600 may not generate anovershoot for the hot feedback output from the second thermoelectriccouple group. In detail, the hot feedback with the first intensity,which is lower than the hot feedback with the second intensity outputfrom the first thermoelectric couple group, is output from the secondthermoelectric couple group. In this case, the temperature of thecontact surface of the second thermoelectric couple group may be thefirst saturation temperature lower than the second saturationtemperature, which is the temperature of the contact surface of thefirst thermoelectric couple group. That is, a temperature differencebetween the contact surface of the first thermoelectric couple group andthe contact surface of the second thermoelectric couple group occurs,and the user may recognize the temperature difference. Accordingly,although the user's senses are disturbed by the hot feedback of thefirst thermoelectric couple group, the user is not affected by the hotfeedback of the first thermoelectric couple group and may recognize thehot feedback output from the second thermoelectric couple group becauseof the temperature difference. Accordingly, when the feedback device1600 confirms that the intensity of the thermal feedback output from thesecond thermoelectric couple group is lower than the intensity of thethermal feedback output from the first thermoelectric couple group, thefeedback device 1600 does not generate an overshoot for the thermalfeedback of the second thermoelectric couple group and may output thethermal feedback with the confirmed intensity.

Referring to FIG. 35B, the feedback device 1600 may temporarily increasethe temperature difference between the contact surface of the firstthermoelectric couple group and the contact surface of the secondthermoelectric couple group. In addition, according to an embodiment,when the temperature difference between the contact surface of the firstthermoelectric couple group and the contact surface of the secondthermoelectric couple group increases, the user may better recognize thethermal feedback output from the second thermoelectric couple group.Accordingly, by using the thermal feedback recognition enhancementmethod, the feedback device 1600 may gradually increase the temperatureof the contact surface of the second thermoelectric couple group totemporarily increase the temperature difference between the contactsurface of the first thermoelectric couple group and the contact surfaceof the second thermoelectric couple group.

According to an embodiment of the present invention, after the feedbackdevice 1600 initiates the output of the hot feedback with the secondintensity from the first thermoelectric couple group at the first timepoint, the second thermoelectric couple group may output the hotfeedback with the first intensity at the second time point. In thiscase, instead of applying an operating temperature (a first forwardvoltage in the example of FIG. 35B) for the hot feedback with the firstintensity to the second thermoelectric couple group between the secondtime point and a fourth time point, the feedback device 1600 may apply athird forward voltage lower than the operating temperature. Thus, thetemperature of the contact surface of the second thermoelectric couplegroup may gradually increase along a third reference temperature curve3510. Subsequently, the feedback device 1600 applies the operatingtemperature to the second thermoelectric couple group at the fourth timepoint so that a temperature increase rate increases on the contactsurface of the second thermoelectric couple group and thus thetemperature of the contact surface of the second thermoelectric couplegroup reaches the first saturation at a fifth time point. As describedabove, as the third forward voltage lower than the operating temperatureis applied to the second thermoelectric couple group between the secondtime point and the fourth time point instead of the operatingtemperature being applied to the second thermoelectric couple group fromthe second time point, the temperature difference between the contactsurface of the first thermoelectric couple group and the contact surfaceof the second thermoelectric couple group increases between the secondtime point and the fourth time point. Thus, the user may betterrecognize the hot feedback output from the second thermoelectric couplegroup. Also, the contact surface of the second thermoelectric couplegroup reaches the first saturation temperature at the third time pointwhen the operating temperature is applied to the second thermoelectriccouple group at the second time point, and the contact surface of thesecond thermoelectric couple group reaches the first saturationtemperature at the fifth time point, which is after the third timepoint, when the third forward voltage is applied to the secondthermoelectric couple group between the second time point and the fourthtime point.

Referring to FIG. 35C, the feedback device 1600 may generate anovershoot for the hot feedback with the first intensity output from thesecond thermoelectric couple group. According to an embodiment, evenwhen the intensity of the thermal feedback output from the secondthermoelectric couple group is lower than the intensity of the thermalfeedback output from the first thermoelectric couple group, thetemperature of the contact surface of the second thermoelectric couplegroup temporarily increases such that the user may better recognize thethermal feedback output from the second thermoelectric couple group. Tothis end, the feedback device 1600 may apply an excessive voltage (asecond forward voltage in the example of FIG. 35C) higher than theoperating voltage (a first forward voltage in the example of FIG. 35C)for the hot feedback with the second intensity to the secondthermoelectric couple group between the second time point and a sixthtime point. Thus, the temperature of the contact surface of the secondthermoelectric couple group may increase along a second referencetemperature curve 3520 from the second time point to the sixth timepoint, and the temperature of the contact surface of the secondthermoelectric couple group at the sixth time point may be higher thanthe first saturation temperature. Subsequently, the operating responsefor the hot feedback with the first intensity is applied at the sixthtime point so that the temperature of the contact surface of the secondthermoelectric couple group may reach the first saturation temperature.In this case, an overshoot of the hot feedback output from the secondthermoelectric couple group may be generated during a time interval inwhich the temperature of the contact surface of the secondthermoelectric couple group increases over the first saturationtemperature. As the overshoot is generated, it is possible to enhancerecognition of the thermal feedback output from the secondthermoelectric couple group.

FIG. 36 is a diagram showing a change in temperature on a contactsurface according to a thermal feedback recognition enhancement methodwhen a hot feedback is output from the first thermoelectric couple groupand a cold feedback is output from the second thermoelectric couplegroup according to an embodiment of the present invention.

Referring to FIG. 36, in portions FIG. 36A and FIG. 36B, a hot feedbackmay be output from the first thermoelectric couple group, and a coldfeedback may be output from the second thermoelectric couple group. Inthis case, the intensity of the hot feedback output from the firstthermoelectric couple group may be the same as or different from theintensity of the cold feedback output from the second thermoelectriccouple group. For convenience of description, the following descriptionassumes that the intensity of the hot feedback output from the firstthermoelectric couple group is the same as the intensity of the coldfeedback output from the second thermoelectric couple group, but thepresent invention is not limited thereto. The description with referenceto FIG. 36 may apply to even a case in which the intensity of the hotfeedback output from the first thermoelectric couple group is differentfrom the intensity of the cold feedback output from the secondthermoelectric couple group. Also, according to the heat transferoperation, the cold feedback may be output from the secondthermoelectric couple group after the output of the hot feedback fromthe first thermoelectric couple group is initiated.

Referring to FIG. 36A, the feedback device 1600 may not generate anovershoot for the cold feedback output from the second thermoelectriccouple group. In detail, the cold feedback, which is opposite to the hotfeedback output from the first thermoelectric couple group, is outputfrom the second thermoelectric couple group. A hot spot of the user'sbody is stimulated by the hot feedback, and a cold spot of the user'sbody is stimulated by the cold feedback. Thus, since the sensory pointof the user affected by the hot feedback output from the firstthermoelectric couple group is different from the sensory point of theuser affected by the cold feedback output from the second thermoelectriccouple group, the user is not affected by the hot feedback of the firstthermoelectric couple group and may recognize the cold feedback outputfrom the second thermoelectric couple group. Accordingly, when thefeedback device 1600 confirms that the type of the thermal feedbackoutput from the second thermoelectric couple group is different from thetype of the thermal feedback output from the first thermoelectric couplegroup, the feedback device 1600 does not generate an overshoot for thethermal feedback of the second thermoelectric couple group and mayoutput the thermal feedback with the confirmed type.

Referring to FIG. 36B, the feedback device 1600 may generate anovershoot for the cold feedback output from the second thermoelectriccouple group. According to an embodiment, even when the type of thethermal feedback output from the second thermoelectric couple group isdifferent from the type of the thermal feedback output from the firstthermoelectric couple group, the difference between the temperature ofthe contact surface of the first thermoelectric couple group and thetemperature of the contact surface of the second thermoelectric couplegroup increases such that the user may better recognize the thermalfeedback output from the second thermoelectric couple group. To thisend, the feedback device 1600 may apply an excessive voltage (a secondreverse voltage in the example of FIG. 36B) higher than the operatingvoltage (a first reverse voltage in the example of FIG. 36B) for thecold feedback with the first intensity to the second thermoelectriccouple group between the second time point and the third time pointduring which the second thermoelectric couple group outputs the coldfeedback. Accordingly, an overshoot of the cold feedback output from thesecond thermoelectric couple group may be generated during a timeinterval in which the temperature of the contact surface of the secondthermoelectric couple group decreases below the first-prime saturationtemperature. The temperature difference between the contact surface ofthe first thermoelectric couple group and the contact surface of thesecond thermoelectric couple group temporarily increases due to thegeneration of the overshoot, and thus it is possible to enhancerecognition of the thermal feedback output from the secondthermoelectric couple group.

FIG. 37 is a diagram showing a change in temperature on a contactsurface according to a thermal feedback recognition enhancement methodwhen a cold feedback is output from the first thermoelectric couplegroup and a hot feedback is output from the second thermoelectric couplegroup according to an embodiment of the present invention.

Referring to FIG. 37, in portions FIG. 37A and FIG. 37B, a cold feedbackmay be output from the first thermoelectric couple group, and a hotfeedback may be output from the second thermoelectric couple group, asopposed to the embodiment of FIG. 36. In this case, the intensity of thecold feedback output from the first thermoelectric couple group may bethe same as, or different from, the intensity of the hot feedback outputfrom the second thermoelectric couple group. For convenience ofdescription, the following description assumes that the intensity of thecold feedback output from the first thermoelectric couple group is thesame as the intensity of the hot feedback output from the secondthermoelectric couple group, but the present invention is not limitedthereto. The description with reference to FIG. 37 may even apply to acase in which the intensity of the cold feedback output from the firstthermoelectric couple group is different from the intensity of the hotfeedback output from the second thermoelectric couple group. Also,according to the heat transfer operation, the hot feedback may be outputfrom the second thermoelectric couple group after the output of the coldfeedback from the first thermoelectric couple group is initiated.

Referring to FIG. 37A, the feedback device 1600 may not generate anovershoot for the hot feedback output from the second thermoelectriccouple group. As described in FIG. 36A, as a user's sensory pointsaffected by the hot feedback and the cold feedback are different fromeach other, the user is not affected by the cold feedback of the firstthermoelectric couple group and may recognize the hot feedback outputfrom the second thermoelectric couple group. Accordingly, when thefeedback device 1600 confirms that the type of the thermal feedbackoutput from the second thermoelectric couple group is different from thetype of the thermal feedback output from the first thermoelectric couplegroup, the feedback device 1600 does not generate an overshoot for thethermal feedback of the second thermoelectric couple group and mayoutput the thermal feedback with the confirmed type.

Referring to FIG. 37B, the feedback device 1600 may generate anovershoot for the hot feedback output from the second thermoelectriccouple group. As shown in FIG. 36B, according to an embodiment, evenwhen the type of the thermal feedback output from the secondthermoelectric couple group is different from the type of the thermalfeedback output from the first thermoelectric couple group, thedifference between the temperature of the contact surface of the firstthermoelectric couple group and the temperature of the contact surfaceof the second thermoelectric couple group increases such that the usermay better recognize the thermal feedback output from the secondthermoelectric couple group. To this end, the feedback device 1600 mayapply an excessive voltage (a second forward voltage in the example ofFIG. 37B) higher than the operating voltage (a first forward voltage inthe example of FIG. 37B) for the hot feedback with the first intensityto the second thermoelectric couple group between the second time pointand the third time point during which the second thermoelectric couplegroup outputs the hot feedback. Accordingly, an overshoot of the hotfeedback output from the second thermoelectric couple group may begenerated during a time interval in which the temperature of the contactsurface of the second thermoelectric couple group increases over thefirst saturation temperature. The temperature difference between thecontact surface of the first thermoelectric couple group and the contactsurface of the second thermoelectric couple group temporarily increasesdue to the generation of the overshoot, and thus it is possible toenhance recognition of the thermal feedback output from the secondthermoelectric couple group.

FIG. 38 is a diagram showing a change in temperature on a contactsurface and a change in applied voltage according to a thermal feedbackrecognition enhancement method when a cold feedback is output from thefirst thermoelectric couple group and the second thermoelectric couplegroup according to an embodiment of the present invention.

The first thermoelectric couple group and the second thermoelectriccouple group may output cold feedbacks with the same intensity or withdifferent intensities. However, according to the heat transferoperation, the cold feedback may be output from the secondthermoelectric couple group after the output of the cold feedback fromthe first thermoelectric couple group is initiated.

According to an embodiment of the present invention, by using thethermal feedback recognition enhancement method, the feedback device1600 may generate an overshoot of the hot feedback output from thesecond thermoelectric couple group when the hot feedback is output fromthe second thermoelectric couple group but may not generate an overshootof the cold feedback output from the second thermoelectric couple groupwhen the cold feedback is output from the second thermoelectric couplegroup.

In detail, depending on the body part, the number of cold spots isgreater than the number of hot spots among the user's sensory spots.Since the number of cold spots is greater, that is, since the number ofcold spots is greater than the number of hot spots at the same body partdue to the cold feedback output from the first thermoelectric couplegroup, the user's senses are less disturbed when the cold feedback isoutput from the first thermoelectric couple group than when the hotfeedback is output from the first thermoelectric couple group. Thus,when the thermal feedback output from the second thermoelectric couplegroup is the cold feedback, the user is not affected by the thermalfeedback output from the first thermoelectric couple group and mayrecognize the cold feedback output from the second thermoelectric couplegroup although an overshoot for the cold feedback output from the secondthermoelectric couple group is not generated. Accordingly, the feedbackdevice 1600 may not generate an overshoot for the cold feedback outputfrom the second thermoelectric couple group.

Referring to FIG. 38, as shown in FIG. 38, a first operating voltage (afirst reverse voltage in the example of FIG. 38) for outputting the coldfeedback may be applied to the first thermoelectric couple group at afirst time point. Also, a second operating voltage (a first reversevoltage in the example of FIG. 38) may be applied to the secondthermoelectric couple group at a second time point, which is after thefirst time point. Thus, an overshoot is not generated in the thermalfeedback of the second thermoelectric couple group, and the temperatureof the contact surface of the first thermoelectric couple group reachesthe first-prime saturation temperature. However, since the number ofcold spots are greater than the number of hot spots although theovershoot is not generated, the user is not affected by the coldfeedback output from the first thermoelectric couple group and mayrecognize the cold feedback output from the second thermoelectric couplegroup.

In summary, with respect to the description with reference to FIG. 38,according to an embodiment of the present invention, the feedback device1600 may perform the thermal feedback recognition enhancement methodaccording to steps S3110 and S3120. In this case, as shown in FIG. 38,in step S3110, the feedback device 1600 may confirm that the type of thethermal feedback output from the second thermoelectric couple group is acold feedback. In this case, in S3120, the feedback device 1600 may notgenerate an overshoot for the cold feedback output from the secondthermoelectric couple group and may apply a predetermined voltage to thesecond thermoelectric couple group in order to output the cold feedback.That is, in S3120, whether the feedback device 1600 generates anovershoot for the thermal feedback output from the second thermoelectriccouple group may be selectively determined according to the type of thethermal feedback output from the second thermoelectric couple group. Inother words, in S3120, the feedback device 1600 may generate anovershoot for the hot feedback when the hot feedback is output from thesecond thermoelectric couple group and may not generate an overshoot forthe cold feedback when the cold feedback is output from the secondthermoelectric couple.

3.3. Time Point at which Excessive Power for Generating an Overshoot ofa Thermal Feedback is Applied

As described above, according to the heat transfer operation, a voltagefor outputting the thermal feedback from the second thermoelectriccouple group may be applied after the output of the thermal feedbackfrom the first thermoelectric couple group is initiated. According tothe present invention, an excessive voltage may be applied to the secondthermoelectric couple group so that the thermal feedback output from thesecond thermoelectric couple group is better recognized by the user. Inthis case, the time point at which the excessive voltage is applied tothe second thermoelectric couple group may be adjusted. A relationbetween the time point at which the excessive voltage is applied to thefirst thermoelectric couple group and the time point at which theexcessive voltage is applied to the second thermoelectric couple groupwill be described below.

FIGS. 39 to 41 are diagrams showing a change in temperature on a contactsurface according to a voltage application time point in the firstthermoelectric couple group and the second thermoelectric couple groupin the thermal feedback recognition enhancement method according to anembodiment of the present invention.

According to an embodiment of the present invention, the firstthermoelectric couple group may output a hot feedback with a firstintensity. Also, according to the heat transfer operation, the hotfeedback may be output from the second thermoelectric couple group afterthe output of the hot feedback from the first thermoelectric couplegroup is initiated.

In detail, the feedback device 1600 may perform the thermal feedbackrecognition enhancement method on the first thermoelectric couple group.The feedback device 1600 may apply, to the first thermoelectric couplegroup, a first excessive voltage (a second forward voltage in theexamples of FIGS. 39 to 41) higher than a first operating voltage (afirst forward voltage in the examples of FIGS. 39 to 41) for outputtingthe hot feedback with the first intensity between the first time pointand the second time point. Thus, the temperature of the contact surfaceof the first thermoelectric couple group increases along a secondreference temperature curve 3920 such that an overshoot interval inwhich the temperature of the contact surface of the first thermoelectriccouple group is higher than the first saturation temperature may occur.Subsequently, a first operating voltage, which is lower than the firstexcessive voltage, is applied to the first thermoelectric couple groupat the second time point such that the temperature of the contactsurface of the first thermoelectric couple group may be lowered to thefirst saturation temperature.

According to the present invention, a time point at which a secondexcessive voltage is applied to a second thermoelectric couple group(here, the second excessive voltage group refers to an excessive voltageapplied to the second thermoelectric couple group) may be adjusted withrespect to a second time point, which is a time point at which the firstoperating voltage, instead of the first excessive voltage, is applied asthe voltage applied to the first thermoelectric couple group.

First, referring to FIG. 39, according to an embodiment of the presentinvention, the second excessive voltage may be applied to the secondthermoelectric couple group at a time point prior to the second timepoint at which the first operating voltage is applied to the firstthermoelectric couple group, that is, while the first excessive voltageis applied to the first thermoelectric couple group. In this case, asecond forward voltage, which is the second excessive voltage, isapplied to the second thermoelectric couple group at a third time point,which is before the second time point, and the second excessive voltagemay be applied up to a fourth time point, which is after the second timepoint. Thus, the temperature of the contact surface of the secondthermoelectric couple group may increase along the second referencetemperature curve 3920 from the second time point to the fourth timepoint, and thus an overshoot interval in which the temperature of thecontact surface of the second thermoelectric couple group is higher thanthe first saturation temperature may occur. In summary, since the secondtime point, which is a time point at which a first driving voltage isapplied to the first thermoelectric couple group, is between the thirdtime point and the fourth point, a time during which the first excessivevoltage is applied to the first thermoelectric couple group may overlapa time during which the second excessive voltage is applied to thesecond thermoelectric couple group. That is, while the second excessivevoltage is applied to the second thermoelectric couple group, thetemperature of the contact surface of the first thermoelectric couplegroup may increase up to the threshold temperature and then decrease.

Subsequently, a first driving voltage, which is lower than the firstexcessive voltage, is applied to the second thermoelectric couple groupat the fourth time point such that the temperature of the contactsurface of the second thermoelectric couple group may be lowered to thefirst saturation temperature.

Referring to FIG. 40, according to an embodiment of the presentinvention, the second excessive voltage may be applied to the secondthermoelectric couple group at a second time point, which is a timepoint at which the first operating voltage is applied to the firstthermoelectric couple group, that is, as soon as the application of thefirst excessive voltage to the first thermoelectric couple group ends.In this case, a second forward voltage, which is the second excessivevoltage, is applied to the second thermoelectric couple group at a thirdtime point, which is the same as the second time point, and the secondexcessive voltage may be applied up to a fourth time point, which isafter the second time point. Thus, the temperature of the contactsurface of the second thermoelectric couple group may increase along thesecond reference temperature curve 3920 from the second time point tothe fourth time point, and thus an overshoot interval in which thetemperature of the contact surface of the second thermoelectric couplegroup is higher than the first saturation temperature may occur. Insummary, since the second time point, which is a time point at which theapplication of the first excessive voltage to the first thermoelectriccouple group ends, is the same as the third time point, which is a timepoint at which the second excessive voltage is applied to the secondthermoelectric couple group, the time during which the first excessivevoltage is applied to the first thermoelectric couple group may notoverlap the time during which the second excessive voltage is applied tothe second thermoelectric couple group, and the time during which thefirst driving voltage is applied to the first thermoelectric couplegroup may overlap the time during which the second excessive voltage isapplied to the second thermoelectric couple group. That is, when thesecond excessive voltage is applied to the second thermoelectric couplegroup, the temperature of the contact surface of the firstthermoelectric couple group may decrease from the threshold temperature.In other words, when the second excessive voltage is applied to thesecond thermoelectric couple group, the temperature of the contactsurface of the first thermoelectric couple group may change indirection.

Referring to FIG. 41, according to an embodiment of the presentinvention, the second excessive voltage may be applied to the secondthermoelectric couple group after a second time point, which is a timepoint at which the first driving voltage is applied to the firstthermoelectric couple group, elapses, that is, at a predetermined timeafter the application of the first excessive voltage to the firstthermoelectric couple group ends. In this case, a second forwardvoltage, which is the second excessive voltage, is applied to the secondthermoelectric couple group at a third time point, which is after thesecond time point, and the second excessive voltage may be applied up toa fourth time point, which is after the second time point. Thus, thetemperature of the contact surface of the second thermoelectric couplegroup may increase along the second reference temperature curve 3920from the second time point to the fourth time point, and thus anovershoot interval in which the temperature of the contact surface ofthe second thermoelectric couple group is higher than the firstsaturation temperature may occur. In summary, since the second excessivevoltage is applied to the second thermoelectric couple group at a thirdtime point, which is after the second time point, which is a time pointat which the application of the first excessive voltage to the firstthermoelectric couple group ends, the time during which the firstexcessive voltage is applied to the first thermoelectric couple groupmay not overlap the time during which the second excessive voltage isapplied to the second thermoelectric couple group, and the time duringwhich the first driving voltage is applied to the first thermoelectriccouple group may overlap the time during which the second excessivevoltage is applied to the second thermoelectric couple group. That is,when the second excessive voltage is applied to the secondthermoelectric couple group, the temperature of the contact surface ofthe first thermoelectric couple group may decrease from the thresholdvoltage or reach the first saturation temperature.

According to experimental observations, a phenomenon was observed inwhich a user better recognizes the thermal feedback output from thesecond thermoelectric couple group when the third time point follows thesecond time point, as shown in FIG. 41, than when the third time pointat which the second excessive voltage is applied to the secondthermoelectric couple group precedes the second time point at which theapplication of the first excessive voltage to the first thermoelectriccouple group ends, as shown in FIG. 39, or than when the third timepoint is the same as the second time point, as shown in FIG. 40. Thismay be because when the third time point follows the second time point,a time interval between the time point at which a threshold temperatureis output on the contact surface of the first thermoelectric couplegroup and the time point at which a threshold temperature is output onthe contact surface of the second thermoelectric couple group islargest, compared to other cases. However, this may differ depending onthe situation in which the thermal feedbacks are output, such as thetypes and intensities of the thermal feedbacks output from the firstthermoelectric couple group and the second thermoelectric couple group.

4. Response Time Reduction Method for Thermal Feedback

A response time reduction method for a thermal feedback according to anembodiment of the present invention will be described below. Here, theresponse time may refer to a period from a time point at which a voltagefor outputting a thermal feedback with a specific intensity is appliedto a thermoelectric couple group, that is, a time point at which athermoelectric operation is initiated to a time point at which thetemperature of the contact surface of the thermoelectric couple groupreaches a saturation temperature (i.e., a target temperature)corresponding to the thermal feedback with the specific intensity. Also,the response time reduction method for the thermal feedback may beunderstood as an operation of reducing the response time.

In detail, as show in the example of FIG. 11, when a forward voltage isapplied to the thermoelectric couple group, the temperature of thecontact surface may rise from an initial temperature up to thesaturation temperature. In this case, the temperature of the contactsurface may rise from the initial temperature up to the saturationtemperature not momentarily or after a predetermined time, that is, theresponse time. In other words, this may mean that the temperature of thecontact surface reaches a specific temperature corresponding to thethermal feedback only at a certain time after the thermoelectricoperation is initiated and it takes a certain time for the user to sensea thermal feedback with an intended intensity.

However, in this case, when the response time is reduced, thetemperature of the contact surface reaches the specific temperaturecorresponding to the thermal feedback for a time shorter than thecertain time after the thermoelectric operation is initiated by thefeedback device 1600 performing the response time reduction method forthe thermal feedback. That is, as the response time is reduced, the usermay quickly sense the thermal feedback with the intended intensity.

Accordingly, the response time reduction method for the thermal feedbackwill be described below. Also, for convenience of description, thefollowing description assumes that the response time reduction method isperformed by the feedback device 1600. However, the present invention isnot limited thereto, and the response time reduction method may beperformed by the content reproduction device 1200 and may be performedby a third apparatus other than the feedback device 1600 and the contentreproduction device 1200.

FIG. 42 is a flowchart showing a method of reducing a response time of athermal feedback according to an embodiment of the present invention.

In FIG. 42, the response time reduction method may include checking thetype and intensity of a thermal feedback output from a thermoelectriccouple group (S4210), applying, to the thermoelectric couple group,reduction power greater than operating power predetermined by the typeand intensity of the thermal feedback during a predetermined time(S4220), and applying the operating power to the thermoelectric couplegroup after the predetermined time elapses (S4230).

In detail, the feedback device 1600 may check the type and intensity ofthe thermal feedback output from the thermoelectric couple group(S4210). As an example, the type of the thermal feedback may be any oneof a hot feedback, a cold feedback, and a thermal grill feedback. Also,the type (forward voltage/reverse voltage) and magnitude of a voltageapplied to the thermoelectric couple group may be predeterminedaccording to the type and intensity of the thermal feedback.

That is, the operating power applied to the thermoelectric couple groupin order to output the thermal feedback (hereinafter, the voltage andcurrent of the operating power are referred to as an “operating voltage”and an “operating current”) may be predetermined according to the typeand intensity of the thermal feedback.

According to an embodiment of the present invention, the feedback device1600 may acquire thermal feedback data from the content reproductiondevice 1200. The thermal feedback data may include information regardingthe types and intensities of thermal feedbacks output fromthermoelectric couple groups and the output start times and/or end timesof the thermal feedbacks. The feedback device 1600 may check the typeand intensity of the thermal feedback output from the thermoelectriccouple group on the basis of the thermal feedback data.

Also, the feedback device 1600 may apply, to the thermoelectric couplegroup, reduction power greater than the operating power predetermined onthe basis of the type and intensity of the thermal feedback during thepredetermined time. Here, the reduction power may refer to power appliedto reduce the response time (hereinafter, the voltage and current of thereduction power are referred to as a “reduction voltage” and a“reduction current”). In this case, the reduction power may be in thesame direction as the operating power. That is, the reduction power maybe a forward voltage when the operating power is a forward voltage, andthe reduction power may be a reverse voltage when the operating power isa reverse voltage.

As described above, when a thermal feedback with a specific intensity isoutput to a thermoelectric couple group, the temperature of the contactsurface of the thermoelectric couple group may reach a saturationtemperature corresponding to the thermal feedback with the specificintensity from an initial temperature after the response time. However,a time during which the user senses the thermal feedback may be delayeddue to the response time. Accordingly, in order to reduce the responsetime, the feedback device 1600 may apply a reduction voltage greaterthan the operating voltage corresponding to the thermal feedback withthe specific intensity during a predetermined time. Thus, it is possibleto reduce the response time.

Also, the feedback device 1600 may apply the operating voltage to thethermoelectric couple group after the predetermined time elapses(S4230). However, the magnitude of the reduction voltage applied to thethermoelectric couple group to reduce the response time, the applicationtime (i.e., the predetermined time) of the reduction voltage, and thelike may differ depending on various situations, for example, the typeand intensity of the thermal feedback output from the thermoelectriccouple group.

Implementations of the response time reduction method for the thermalfeedback in the various situations will be described below. Also, forconvenience of description, the following description focuses on a casein which a hot feedback is to be output from the thermoelectric couplegroup. However, the present invention is not limited thereto, and itwill be appreciated that the following description may be even appliedto cases in which a cold feedback or a thermal grill feedback is to beoutput from the thermoelectric couple group.

4.1. Implementation of Response Time Reduction Method for ThermalFeedback

FIG. 43 is a diagram showing a change in temperature on a contactsurface and a change in applied voltage according to the method ofreducing a response time of a thermal feedback when a hot feedback isoutput from a thermoelectric couple group according to an embodiment ofthe present invention.

Referring to FIG. 43, the thermoelectric couple group may output a hotfeedback with a first intensity. To this end, the feedback device 1600may apply, to the thermoelectric couple group, an operating voltage (afirst forward voltage in the example of FIG. 43) for outputting the hotfeedback with the first intensity. As the operating voltage is appliedto the thermoelectric couple group, the temperature of the contactsurface of the thermoelectric couple group may reach the firstsaturation temperature at a first response time end point. Thus, theperiod from the first time point to the first response time end pointmay be a response time of the thermal feedback applied to thethermoelectric couple group (hereinafter referred to as a first responsetime).

According to an embodiment of the present invention, the feedback device1600 may perform the thermal feedback response time reduction method inorder to reduce a response rate. In detail, the feedback device 1600 mayapply a reduction voltage (a second forward voltage in the example ofFIG. 43) higher than the operating voltage between the first time pointand a second time point, which corresponds to a predetermined timeinterval. As the reduction voltage is applied to the thermoelectriccouple group, the temperature of the contact surface of thethermoelectric couple group may rise along a second referencetemperature curve 4320. That is, between the first time point and thesecond time point, a temperature rise rate of the contact surface whenthe reduction voltage is applied to the thermoelectric couple group maybe faster than a temperature rise rate of the contact surface when theoperating voltage is applied to the thermoelectric couple group. At thesecond time point, the feedback device 1600 may stop the application ofthe reduction voltage and apply the operating voltage to thethermoelectric couple group. Accordingly, a temperature rise rate of thecontact surface of the thermoelectric couple group after the second timepoint may become slower than a temperature rise rate of the contactsurface of the thermoelectric couple group from the first time point tothe second time point such that the temperature of the contact surfacemay reach the first saturation temperature at a second response time endpoint. In this case, the second response time end point may precede thefirst response time end point. This is because the second forwardvoltage higher than the first forward voltage is applied to thethermoelectric couple group from the first time point to the second timepoint. Accordingly, the period from the first time point to the secondresponse time end point may be a response time (hereinafter referred toas the second response time), and the second response time may be morereduced than the first response time. Thus, the user may sense the hotfeedback as quickly as a reduction time, which is a difference betweenthe first response time and the second response time. Also, when thetemperature of the contact surface of the thermoelectric couple groupreaches the target temperature not gradually but quickly, the user'scognition of the thermal feedback may be enhanced in terms of the user'ssenses. Thus, by the response time being reduced due to the applicationof the second forward voltage, the user may more clearly recognize thethermal feedback.

According to an embodiment of the present invention, the magnitude ofthe reduction voltage (a second forward voltage in the example of FIG.43) applied to reduce the response time may be predetermined. Forexample, as shown in the example of FIG. 43, the reduction voltage maybe a voltage that is one step higher than the operating voltage (a firstforward voltage in the example of FIG. 43) indicating a voltage with anintended intensity, that is, a voltage of the target intensity, and maybe a voltage that is multiple-steps higher than the operating voltage.Also, the reduction voltage may be predetermined irrespective of theintensity of the thermal feedback. For example, the reduction voltagemay be higher than the operating voltage by a predetermined value. Also,the ratio of the operating voltage to the reduction voltage may bepredetermined.

In addition, since the reduction voltage is predetermined, a temperature(a second saturation temperature in the example of FIG. 43)corresponding to the reduction voltage may also be predetermined.

Likewise, the temperature corresponding to the reduction voltage may bea temperature that is determined to output a thermal feedback with apredetermined intensity and may be a temperature that is not related tothe thermal feedback with the predetermined intensity. Also, thetemperature corresponding to the reduction voltage may be higher thanthe saturation temperature corresponding to the operating voltage by apredetermined value, and the ratio of the temperature corresponding tothe reduction voltage to the saturation temperature corresponding to theoperating voltage may be predetermined.

Also, according to an embodiment of the present invention, the feedbackdevice 1600 may determine the magnitude of the reduction voltage so thatthe temperature of the contact surface does not exceed a saturationtemperature corresponding to the operating voltage. This is because whenthe temperature of the contact surface exceeds the saturationtemperature corresponding to the operating voltage, the user maymisunderstand that a thermal feedback with other intensity is output.According to an embodiment, the feedback device 1600 may determine themagnitude of the reduction voltage so that the temperature of thecontact surface does not reach the saturation temperature correspondingto the operating voltage while the reduction voltage is applied. Whenthe temperature of the contact surface does not reach the saturationtemperature corresponding to the operating voltage while the reductionvoltage is applied, the temperature of the contact surface does notexceed the saturation temperature after the application of the reductionvoltage ends and then the operating voltage is applied.

Also, according to an embodiment of the present invention, a time pointat which the application of the reduction voltage is stopped, that is, atime point at which the operating voltage is applied, may bepredetermined. According to an embodiment of the present invention, thetime point at which the application of the reduction voltage is stoppedmay be determined depending on a threshold temperature indicating thetemperature of the contact surface at the second time point. That is,the time point at which the application of the reduction voltage isstopped affects the threshold temperature, and thus the time point atwhich the application of the reduction voltage is stopped may bepredetermined in consideration of a relation between the thresholdtemperature and the time point at which the application of the reductionvoltage is stopped. For example, the feedback device 1600 may stopapplying the reduction voltage when the temperature of the contactsurface 1641 reaches a predetermined threshold temperature.

Also, as another example, the feedback device 1600 may determine thetime point at which application of the reduction voltage is stopped,that is, a reduction voltage application time so that the temperature ofthe contact surface does not reach the saturation temperaturecorresponding to the operating voltage while the reduction voltage isapplied. As described above, when the temperature of the contact surfacedoes not reach the saturation temperature corresponding to the operatingvoltage while the reduction voltage is applied, the temperature of thecontact surface does not exceed the saturation temperature after theapplication of the reduction voltage ends and then the operating voltageis applied.

However, according to an embodiment, the reduction voltage and the timepoint at which the application of the reduction voltage is stopped maybe determined so that the threshold temperature is lower than thesaturation temperature corresponding to the operating voltage.

Also, according to another embodiment of the present invention, the timepoint at which the application of the reduction voltage is stopped maybe determined on the basis of the target intensity. For example, thetime point at which the application of the reduction voltage is stoppedmay be t seconds when the target intensity is the first intensity andmay be t+a seconds (or t−a seconds) when the target intensity is thesecond intensity.

Also, according to an embodiment of the present invention, whether toapply the voltage to the thermoelectric couple group for response timereduction may be determined depending on the intensity of the thermalfeedback, that is, the magnitude of the operating voltage. For example,when the intensity of the thermal feedback is lower than a predeterminedintensity, the temperature of the contact surface may quickly reach thesaturation temperature although the reduction voltage is not applied. Inthis case, the effect of reducing the response time according to theapplication of the reduction voltage is small. Thus, when the intensityof the thermal feedback is lower than the predetermined intensity, thefeedback device 1600 may not apply the reduction voltage. Likewise, whenthe intensity of the thermal feedback is higher than the predeterminedintensity, the feedback device 1600 may apply the reduction voltage tothe thermoelectric couple group in order to reduce the response timebecause the effect of reducing the response time according to theapplication of the reduction voltage is large.

FIG. 44 is a diagram showing a change in temperature on a contactsurface and a change in applied voltage according to the method ofreducing a response time of a thermal feedback when a hot feedback isoutput from a thermoelectric couple group according to anotherembodiment of the present invention.

Referring to FIG. 44, the feedback device 1600 may apply, to athermoelectric couple group, an operating voltage (a first forwardvoltage in the example of FIG. 44) for outputting a hot feedback with afirst intensity, and the temperature of the contact surface of thethermoelectric couple group may reach a first saturation temperature ata first response time end point. Thus, the period from the first timepoint to the first response time end point may be a response time of thethermal feedback applied to the thermoelectric couple group (hereinafterreferred to as a first response time Δtr1).

Also, according to an embodiment of the present invention, the feedbackdevice 1600 may apply a first reduction voltage (a second forwardvoltage in the example of FIG. 44) higher than a first operating voltagebetween a first time point and a second time point, and the temperatureof the contact surface of the thermoelectric couple group may rise alonga second reference temperature curve 4420 to reach the first saturationtemperature at a second response time end point preceding the firstresponse time end point. The period from the first time point to thesecond response time end point may be a response time of the thermalfeedback applied to the thermoelectric couple group (hereinafterreferred to as a second response time Δtr2), and the second responsetime may be reduced by a first reduction time in comparison with thefirst response time Δtr1.

Also, according to another embodiment of the present invention, thefeedback device 1600 may apply a second reduction voltage (a thirdforward voltage in the example of FIG. 44) higher than the firstreduction voltage between the first time point and the second timepoint, and the temperature of the contact surface of the thermoelectriccouple group may rise along a third reference temperature curve 4430 toreach the first saturation temperature at a third response time endpoint preceding the second response time end point. The period from thefirst time point to the third response time end point may be a responsetime of the thermal feedback applied to the thermoelectric couple group(hereinafter referred to as a third response time Δtr3), and the thirdresponse time may be reduced by a second reduction time in comparisonwith the first response time. Also, the third response time may be morereduced than the second response time.

Likewise, even when a fourth forward voltage or a fifth forward voltage,which is higher than the first forward voltage, is applied between thefirst time point and the second time point, the response time may bereduced.

According to an embodiment of the present invention, the differencebetween the first saturation temperature and the temperature at the timepoint at which the application of the reduction voltage ends may bewithin a predetermined range. As an example, the difference between thefirst saturation temperature and the temperature at the second timepoint, which is a time point at which the application of the reductionvoltage ends, may differ depending on the magnitude of the reductionvoltage. For example, a first temperature difference ΔTd1 may occur whenthe second forward voltage is applied as the reduction voltage betweenthe first time point and the second time point, and a fourth temperaturedifference ΔTd4 may occur when the fifth forward voltage is applied asthe reduction voltage. In this case, the first temperature differencemay be greater than the fourth temperature difference. This is becauseas the magnitude of the reduction voltage increases, the temperaturerise rate increases and thus the difference between the first saturationtemperature and the temperature at the second time point decreases.

According to a specific embodiment of the present invention, thetemperature at the second time point may be predetermined as a specificratio with respect to the first saturation temperature. For example, thetemperature at the second time point when the reduction voltage is afifth forward voltage may be 95% of the first saturation temperature,the temperature at the second time point when the reduction voltage is afourth forward voltage may be 90% of the first saturation temperature,the temperature at the second time point when the reduction voltage is athird forward voltage may be 85% of the first saturation temperature,and the temperature at the second time point when the reduction voltageis a second forward voltage may be 80% of the first saturationtemperature. In an experiment example, when an ambient temperature wasroom temperature and the temperature at the second time point when thereduction voltage was applied was 70% or more of the first saturationtemperature, the user's cognition of the thermal feedback was enhanced.This may be because the response time is reduced as the temperature atthe second time point approaches the first saturation temperature. Thatis, as the temperature at the second time point approaches the firstsaturation temperature, a temperature variation experienced by the userincreases. Thus, the user's cognition of the thermal feedback may beenhanced. According to the above experiment example, in order to enhancethe user's cognition, the magnitude of the reduction voltage may be setto a voltage at which the temperature at the second time point becomes70% or more and less than 100% of the first saturation temperature.

Also, according to another specific embodiment of the present invention,a ratio of a first application time during which the reduction voltageis applied to a second application time during which a voltage (a firstforward voltage in the example of FIG. 44) other than the reductionvoltage is applied until the temperature of the contact surface reachesthe first saturation temperature may be predetermined. For example, theratio of the first application time to the second application time maybe set to 1:X (here, X is less than or equal to 1). It will beappreciated that, according to another embodiment, the ratio of thefirst application time to the second application time may be set to 1:Y(here, Y is greater than 1). In an experiment example, when an ambienttemperature was room temperature and the ratio of the first applicationtime to the second application time was set to 1:Z (here, Z was greaterthan or equal to 0.05 and less than or equal to 0.95), the user'scognition of the thermal feedback was enhanced. Thus, according to anembodiment, in order to enhance the user's cognition, the ratio of thefirst application time to the second application time may be set to 1:Z(here, Z is greater than or equal to 0.1 and less than or equal to 0.9).

Also, according to an embodiment of the present invention, the ratio ofthe reduction voltage (the second to fifth forward voltages) to thefirst forward voltage may be predetermined. For example, the secondforward voltage may be less than two times the first forward voltage.

Also, according to an embodiment of the present invention, thetemperature at the second time point corresponding to each of aplurality of reduction voltages may be prestored. In this case, thefeedback device 1600 may set the magnitude of the reduction voltage sothat the temperature at the second time point reaches a specifictemperature with reference to the prestored information.

In summary, as the magnitude of the voltage applied between the firsttime point and the second time point, that is, the reduction voltage forreducing the response time, increases, the response time of the thermalfeedback may be reduced. Thus, the user may sense the thermal feedbackat an earlier time.

However, when the magnitude of the reduction voltage increases over apredetermined critical voltage, the temperature of the contact surfaceof the thermoelectric couple group may be higher than a first saturationtemperature. According to an embodiment of the present invention, thefeedback device 1600 may adjust the magnitude of the reduction voltageso that the temperature of the contact surface of the thermoelectriccouple group does not exceed the first saturation temperature.

FIG. 45 is a diagram showing a change in temperature on a contactsurface and a change in applied voltage according to the method ofreducing a response time of a thermal feedback when a hot feedback isoutput from a thermoelectric couple group according to still anotherembodiment of the present invention.

Referring to FIG. 45, the feedback device 1600 may apply, to athermoelectric couple group, an operating voltage (a first forwardvoltage in the example of FIG. 45) for outputting a hot feedback with afirst intensity, and the temperature of the contact surface of thethermoelectric couple group may reach a first saturation temperature ata first response time end point. Thus, the period from the first timepoint to the first response time end point may be a response time of thethermal feedback applied to the thermoelectric couple group (hereinafterreferred to as a first response time).

Also, according to an embodiment of the present invention, the feedbackdevice 1600 may apply a reduction voltage (a second forward voltage inthe example of FIG. 45) higher than the operating voltage between thefirst time point and a second time point, and the temperature of thecontact surface of the thermoelectric couple group may rise along asecond reference temperature curve 4520 to reach the first saturationtemperature at a second response time end point preceding the firstresponse time end point. The period from the first time point to thesecond response time end point may be a response time of the thermalfeedback applied to the thermoelectric couple group (hereinafterreferred to as a second response time Δtr2), and the second responsetime may be reduced by a first reduction time in comparison with thefirst response time Δtr1.

Also, according to an embodiment of the present invention, the feedbackdevice 1600 may apply the reduction voltage from the first time pointand may apply the reduction voltage up to a third time point which isafter the second time point. In this case, the temperature of thecontact surface may rise up to the third time point along the secondreference temperature curve 4520 to reach the first saturationtemperature at a third response time end point preceding the secondresponse time end point. The period from the first time point to thethird response time end point may be a response time of the thermalfeedback applied to the thermoelectric couple group (hereinafterreferred to as a third response time Δtr3), and the third response timemay be reduced by a second reduction time in comparison with the firstresponse time. Also, the third response time Δtr3 may be more reducedthan the second response time.

Likewise, even when the reduction voltage is applied even to the fourthtime point or the fifth time point, which is after the third time point,the response time may be reduced.

According to an embodiment of the present invention, the differencebetween the first saturation temperature and the temperature at the timepoint at which the application of the reduction voltage ends may bewithin a predetermined range. As an example, the difference between thefirst saturation temperature and the temperature at the time point atwhich the application of the reduction voltage ends may differ dependingon the time during which the reduction voltage is applied. For example,when the reduction voltage is applied from a first time point to asecond time point, a first temperature difference ΔTd1 may occur betweenthe first saturation temperature and the temperature at the second timepoint, and when the reduction voltage is applied from a first time pointto a fifth time point, a fourth temperature difference ΔTd4 may occurbetween the first saturation temperature and the temperature at thefifth time point. In this case, the first temperature difference may begreater than the fourth temperature difference. This is because atemperature rise rate when the reduction voltage is applied is fasterthan a temperature rise rate when a non-reduction voltage, that is, thefirst forward voltage, is applied.

According to a specific embodiment of the present invention, thetemperature at the time point at which the application of the reductionvoltage ends may be predetermined as a specific ratio with respect tothe first saturation temperature. For example, the temperature at afifth time point when the reduction voltage is applied up to the fifthtime point may be 95% of the first saturation temperature, thetemperature at a fourth time point when the reduction voltage is appliedup to the fourth time point may be 90% of the first saturationtemperature, the temperature at a third time point when the reductionvoltage is applied up to the third forward voltage may be 85% of thefirst saturation temperature, and the temperature at a second time pointwhen the reduction voltage is applied up to the second forward voltagemay be 80% of the first saturation temperature. In an experimentexample, when an ambient temperature was room temperature and thetemperature at the time point at which application of the reductionvoltage ended was 70% or more of the first saturation temperature, theuser's cognition of the thermal feedback was enhanced.

This may be because the response time is reduced as the temperature atthe time point at which the application of the reduction voltage endsapproaches the first saturation temperature. That is, as the temperatureat the time point at which the application of the reduction voltage endsapproaches the first saturation temperature, a temperature variationexperienced by the user increases. Thus, the user's cognition of thethermal feedback may be enhanced. According to the above experimentexample, in order to enhance the user's cognition, the time during whichthe reduction voltage is applied may be set to the time it takes for thetemperature to reach 70% or more and less than 100% of the firstsaturation temperature.

Also, according to another specific embodiment of the present invention,a ratio of a first application time, during which the reduction voltageis applied to a second application time during which a voltage (a firstforward voltage in the example of FIG. 45) other than the reductionvoltage is applied until the temperature of the contact surface reachesthe first saturation temperature, may be predetermined. For example, theratio of the first application time to the second application time maybe set to 1:X (here, X is less than or equal to 1). It will beappreciated that, according to another embodiment, the ratio of thefirst application time to the second application time may be set to 1:Y(here, Y is greater than 1). In an experiment example, when an ambienttemperature was room temperature and the ratio of the first applicationtime to the second application time was set to 1:Z (here, Z was greaterthan or equal to 0.05 and less than or equal to 0.9), the user'scognition of the thermal feedback was enhanced. Thus, according to anembodiment, in order to enhance the user's cognition, the ratio of thefirst application time to the second application time may be set to 1:Z(here, Z is greater than or equal to 0.05 and less than or equal to0.95).

Also, according to an embodiment of the present invention, thetemperature according to the time during which each of a plurality ofreduction voltages is applied may be prestored. In this case, thefeedback device 1600 may set the application time of the reductionvoltage on the basis of the prestored information so that the reductionvoltage is applied until the temperature of the contact surface reachesa specific temperature.

Also, according to another embodiment of the present invention, thefeedback device 1600 may include a temperature sensor capable of sensingthe temperature of the contact surface. In this case, after thereduction voltage is applied, the feedback device 1600 may measure thetemperature of the contact surface using the temperature sensor. Whenthe temperature of the contact surface reaches a specific temperature(e.g., 70% of the first saturation temperature), the feedback device1600 may stop the application of the reduction voltage.

In summary, as the time during which the reduction voltage is appliedincreases, the response time of the thermal feedback may be reduced.Thus, the user may sense the thermal feedback at an earlier time.

However, when the time during which the reduction voltage is appliedexceeds a predetermined critical time, the temperature of the contactsurface of the thermoelectric couple group may increase over the firstsaturation temperature. According to an embodiment of the presentinvention, the feedback device 1600 may adjust the time during which thereduction voltage is applied so that the temperature of the contactsurface of the thermoelectric couple group does not exceed the firstsaturation temperature.

FIG. 46 is a diagram showing a change in temperature on a contactsurface and a change in applied voltage according to the method ofreducing a response time of a thermal feedback when a cold feedback isoutput from a thermoelectric couple group according to an embodiment ofthe present invention.

Referring to FIG. 46, a cold feedback with a first intensity may beoutput from the thermoelectric couple group. To this end, the feedbackdevice 1600 may apply, to a thermoelectric couple group, an operatingvoltage (a first reverse voltage in the example of FIG. 46) foroutputting a cold feedback with a first intensity, and the temperatureof the contact surface of the thermoelectric couple group may reach afirst-prime saturation temperature at a first response time end point.In this case, the period from the first time point to the first responsetime end point may be a response time of the thermal feedback applied tothe thermoelectric couple group (hereinafter referred to as a firstresponse time).

As is the case in which a hot feedback is output from a thermoelectriccouple group, the feedback device 1600 may apply a reduction voltage (asecond reverse voltage in the example of FIG. 46) higher than theoperating voltage between the first time point and a second time point,which corresponds to a predetermined time interval, by using the thermalfeedback response time reduction method. As the reduction voltage isapplied to the thermoelectric couple group, the temperature of thecontact surface of the thermoelectric couple group may drop along asecond reference temperature curve 4620 at a rate faster than atemperature drop rate of the contact surface when the first reversevoltage is applied to the thermoelectric couple group. At the secondtime point, the feedback device 1600 may stop the application of thereduction voltage and apply the operating voltage to the thermoelectriccouple group. Accordingly, a temperature drop rate of the contactsurface of the thermoelectric couple group after the second time pointmay become slower than a temperature drop rate of the contact surface ofthe thermoelectric couple group from the first time point to the secondtime point such that the temperature of the contact surface may reachthe first-prime saturation temperature at a second response time endpoint.

As is the case in which a hot feedback is output from a thermoelectriccouple group, the second response time end point may precede the firstresponse time end point. Accordingly, the period from the first timepoint to the second response time end point may be a response time(hereinafter referred to as a second response time), and the secondresponse time may be more reduced than the first response time. Thus,the user may sense the cold feedback as quickly as a reduction time,which is a difference between the first response time and the secondresponse time.

According to an embodiment of the present invention, the magnitude ofthe reduction voltage applied for the response time reduction may bepredetermined, and also the temperature corresponding to the reductionvoltage may be predetermined. Also, a time point at which theapplication of the reduction voltage is stopped, that is, a time pointat which the operating voltage, which is a voltage with an intendedintensity, is applied may be predetermined.

Also, according to an embodiment of the present invention, a voltagehigher than the reduction voltage may be applied at the first time pointin order to reduce the response time. The description with reference toFIGS. 43 to 45 may be applied to various implementations as it is, andthus a detailed description thereof will be omitted.

FIG. 47 is a diagram showing a change in temperature on a contactsurface and a change in applied voltage according to a response timereduction method for a thermal feedback when a thermal grill feedback isoutput from a thermoelectric couple group according to an embodiment ofthe present invention.

Referring to FIG. 47, a thermal grill feedback with a first intensitymay be output from a first thermoelectric couple group and a secondthermoelectric couple group. When the neutral ratio is set to 2, thefeedback device 1600 may apply, to the first thermoelectric couplegroup, a first operating voltage (a first forward voltage in the exampleof FIG. 47) for outputting a hot feedback with a first intensity and mayapply, to the second thermoelectric couple group, a second operatingvoltage (a fourth reverse voltage in the example of FIG. 47) foroutputting a cold feedback with a second intensity. Thus, thetemperature of the contact surface of the first thermoelectric couplegroup may reach the first saturation temperature at the first responsetime end point, and the temperature of the contact surface of the secondthermoelectric couple group may reach the second-prime saturationtemperature at the first response time end point. In this case, theperiod from the first time point to the first response time end pointmay be a response time of the thermal grill feedback output from thefirst thermoelectric couple group and the second thermoelectric couplegroup (hereinafter referred to as a first response time).

Also, between the first time point and the second time point, whichcorresponds to a predetermined time interval, the feedback device 1600may apply a first reduction voltage (a second forward voltage in theexample of FIG. 48) higher than the first operating voltage to the firstthermoelectric couple and may apply a second reduction voltage (a fourthreverse voltage) higher than the second operating voltage to the secondthermoelectric couple group by using the thermal feedback response timereduction method.

As the first reduction voltage is applied to the first thermoelectriccouple group, the temperature of the contact surface of the firstthermoelectric couple group may rise along a second referencetemperature curve 4720 at a rate faster than a temperature rise rate ofthe contact surface when the first operating voltage is applied to thefirst thermoelectric couple group. Also, as the second reduction voltageis applied to the second thermoelectric couple group, the temperature ofthe contact surface of the second thermoelectric couple group may dropalong a fourth reference temperature curve 4740 at a rate faster than atemperature drop rate of the contact surface when the second operatingvoltage is applied to the second thermoelectric couple group. Thus, thetemperature of the contact surface of the first thermoelectric couplegroup may reach the first saturation temperature at the second responsetime end point preceding the first response time end point, and thetemperature of the contact surface of the second thermoelectric couplegroup may reach the second-prime saturation temperature at the secondresponse time end time. That is, the period from the first time point tothe second response time end point may be a response time (hereinafterreferred to as the second response time), and the second response timemay be more reduced than the first response time. The user may sense thethermal grill feedback as quickly as a reduction time, which is adifferent between the first response time and the second response time.

However, for convenience of description, it is assumed that a time pointat which the temperature of the contact surface of the firstthermoelectric couple group reaches the first saturation temperature anda time point at which the temperature of the contact surface of thesecond thermoelectric couple group reaches the second-prime saturationtemperature coincide with each other, that is, the time points are thesame first response time end point (or second response time end point),but the present invention is not limited thereto. The time point atwhich the temperature of the contact surface of the first thermoelectriccouple group reaches the first saturation temperature and the time pointat which the temperature of the contact surface of the secondthermoelectric couple group reaches the second-prime saturationtemperature may not coincide with each other. Even in this case, whenthe response time reduction method for the thermal feedback isperformed, the time it takes for the temperature of the contact surfaceof the first thermoelectric couple group to reach the first saturationtemperature and the time it takes for the temperature of the contactsurface of the second thermoelectric couple group to reach thesecond-prime saturation temperature are reduced. Thus, a response timefor the thermal grill feedback is reduced so that the user mayexperience the thermal grill feedback at an earlier time.

4.2. Thermal Experience Providing Method Considering Reduced ResponseTime

According to an embodiment of the present invention, it may be importantto output an appropriate thermal feedback as multimedia content isreproduced, in order to provide the user with an enhanced thermalexperience. For example, when a video is reproduced, it may be importantto provide a hot feedback for an explosion scene and provide a coldfeedback for a cold scene by linking a thermal feedback to a reproducedscreen.

In detail, in order to associate a thermal feedback with an image orvoice when video content is reproduced, it may be important tosynchronize the thermal feedback with a specific scene or voice to belinked to the thermal feedback. For example, in order for a hot feedbackto be felt when an explosion scene is reproduced, it is desirable that atime point at which the explosion scene is output coincides with a timepoint at which the hot feedback is sensed; otherwise, the user'sexperience may be hindered.

However, when the feedback device 1600 applies power for outputting thethermal feedback at a time point at which a specific scene is output, atime difference may occur between the time point at which the specificscene is output and the time point at which the thermal feedback issensed. This is because even if power is applied to a thermoelectriccouple group, it takes some time before the temperature of a contactsurface 1641 reaches a temperature at which a user can sense a thermalfeedback. That is, the power application time point may not coincidewith the time point at which the user senses the thermal feedback. Thus,when the power application time point coincides with the time point atwhich a specific scene is output, the image and the thermal feedback areout of synchronization. Hereinafter, the time it takes for the user tosense a thermal feedback after initiation of a thermoelectric operationfor the thermal feedback is referred to as a “delay time.”

Hereinafter, also, a specific scene being linked to a thermal feedbackto enhance a user experience is referred to as a thermal event scene.Generally, but not necessarily, for the thermal event scene, eventsinvolving heat in the real world, such as explosions or gunshot hits,are included in the image. Accordingly, any scene capable of beinglinked to the thermal feedback may be included in order to enhance auser's immersion. Similarly, a specific voice in which a user experienceis enhanced by being linked to the thermal feedback is referred to as athermal event voice.

According to an embodiment of the present invention, by using thethermal feedback response time reduction method, the time differencebetween the time point at which the specific scene is output and thetime point at which the thermal feedback is sensed may be decreased. Indetail, FIG. 48 is a diagram showing a thermal feedback output operationaccording to an embodiment of the present invention.

Referring to FIG. 48, FIG. 48A relates to a thermal feedback outputoperation when the thermal feedback response time reduction method isnot performed. In FIG. 48A, when power is applied to a thermoelectriccouple group at a thermal feedback initiation time point, thetemperature of the contact surface of the thermoelectric couple groupmay reach a sensible temperature from an initial temperature during afirst delay time. A thermal event scheme may be reproduced in thecontent reproduction device 1200 when the sensible temperature isreached. Subsequently, the temperature of the contact surface may reacha saturation temperature, and a period from the thermal feedbackinitiation time point to a saturation temperature arrival time point maybe a response time.

FIG. 48B relates to a thermal feedback output operation when the thermalfeedback response time reduction method is performed. In FIG. 48B, likeFIG. 48A, power may be applied to a thermoelectric couple group at athermal feedback initiation time point. In this case, the temperature ofthe contact surface of the thermoelectric couple group may reach asaturation temperature after a second response time elapses from thethermal feedback initiation time point. In this case, by performing thethermal feedback response time reduction method, the second responsetime may be shorter than the first response time in FIG. 48A. Also, asthe second response time decreases, the temperature of the surface areamay reach the sensible temperature at an earlier time point, and alsothe second delay time, which indicates a period from the thermalfeedback initiation time point to the sensible temperature arrival timepoint, may be reduced.

In FIG. 48A and FIG. 48B, when the thermal feedbacks are initiated atthe same time and the thermal feedback response time reduction method isperformed, the delay time is reduced, and thus the thermal eventinitiation time point may be advanced. That is, depending on whether thethermal feedback response time reduction method is performed, whether athermal event scene reproduction time point coincides with a thermalevent sensing time point may be determined. For example, when thethermal feedback response time reduction method is performed and thethermal feedback initiation time point is not adjusted, the thermalevent scene reproduction time point is not synchronized with the thermalevent sensing time point.

A method of providing a thermal experience in consideration of a reducedresponse time point when the thermal event response time reductionmethod is performed will be described below.

FIG. 49 is a flowchart showing a thermal experience providing methodconsidering a reduced response time according to an embodiment of thepresent invention.

Referring to FIG. 49, the thermal experience providing methodconsidering the reduced response time may include loading video contentthat includes image data including a thermal event scene and thermalfeedback data including a thermal feedback linked to the thermal eventscene (S4910), outputting an image according to the image data (S4920),acquiring a time point at which the thermal feedback is to be sensed(S4930), calculating a correction time in consideration of a responsetime of the thermal feedback (S4940), calculating an initiation timepoint of the thermal feedback on the basis of the correction time and atime point at which the thermal feedback is sensed (S4950), transmittinga thermal feedback initiation signal when a thermoelectric operation isinitiated (S4960), and initiating the thermoelectric operation to outputthe thermal feedback according to the thermal feedback initiation signal(S4970).

The aforementioned steps of the embodiment will be described in detailbelow.

The content reproduction device 1200 may load video content thatincludes image data including a thermal event scene and thermal feedbackdata including a thermal feedback linked to the thermal event scene(S4910)

In detail, the controller 1260 may load video content prestored in thememory 1240 or may receive video content through the communicationmodule 1220 in a downloading or streaming manner.

The video content may include the image data and the thermal feedbackdata. Here, the video content may be provided in the form of a singlefile including the image data and the thermal feedback data and also maybe provided in a form that includes a video file including the imagedata and a separate file including the thermal feedback data.

The image data includes information regarding a scene to be output whenthe video content is reproduced. Also, the scene to be output mayinclude a thermal event scene.

The thermal feedback data includes information regarding a thermalfeedback to be output when the video content is reproduced, that is,thermal feedback information. For example, the thermal feedbackinformation may include information regarding a thermal feedback target,a thermal feedback type, a thermal feedback intensity, and a thermalfeedback sensing time point. According to an embodiment, the thermalfeedback sensing time point may be set to be the same as the thermalevent scene reproduction time point.

The content reproduction device 1200 may output an image according tothe image data (S4920). For example, the controller 1260 may decode theimage data with an image codec to output the image. The output of theimage may be performed through an external or internal display.

The content reproduction device 1200 may acquire a time point at whichthe thermal feedback is to be sensed (S4930). In detail, the controller1260 may acquire a time point at which a user should sense the thermalfeedback from the thermal feedback data. Here, the time point at whichthe thermal feedback is sensed may be the same as a time point at whicha specific scene to be linked to the thermal feedback is output.

The content reproduction device 1200 may calculate a correction time inconsideration of a response time of the thermal feedback. Here, thecorrection time may be a time interval from a power application timepoint at which power is applied to the thermoelectric couple group up toa sensing time point at which the temperature of the contact surface1641 reaches a temperature at which a user may sense the thermalfeedback.

In detail, as described above, when the thermal feedback response timereduction method is performed on the feedback device 1600, the delaytime may be reduced. Accordingly, the controller 1260 may determine thedelay time in consideration of whether the thermal feedback responsetime reduction method is performed on the feedback device 1600.

To this end, the controller 1260 may acquire information regarding aresponse time of the feedback device 1600 from the feedback device 1600through the communication module 1220. When the thermal feedbackresponse time reduction method is performed on the feedback device 1600,the controller 1260 may reduce a correction time according to thereduced delay time. For example, when a correction time table isprestored in the memory 1240 and a correction time corresponding to thereduced delay time is stored in the correction time table, thecontroller 1260 may determine the correction time with reference to theprestored correction time table. Also, the correction time may be setdifferently in the correction time table on the basis of the type of thethermal feedback and/or the intensity of the thermal feedback, andinformation regarding the reduced delay time may be reflected in thecorrection time. In this case, the controller 1260 may determine thecorrection time with reference to the prestored correction time table.

Also, when the feedback device 1600 has correction time information thatreflects the reduced delay time and that is stored therein, thecontroller 1260 may receive the correction time information from thefeedback device 1600 and may set the correction time with reference tothe received correction time information.

Also, since a degree to which the response time is reduced may be setdifferently depending on unique characteristics of the feedback device1600, the controller 1260 may determine the correction time inconsideration of identification information of the feedback device 1600.To this end, the controller 1260 may acquire the identificationinformation of the feedback device 1600 through the communication module1220, acquire a delay time of the feedback device 1600 through theidentification information of the feedback device 1600, and determinethe correction time on the basis of the acquired delay time.

Also, the content reproduction device 1200 may calculate an initiationtime point of a thermoelectric operation for the thermal feedback on thebasis of the correction time and the thermal feedback sensing time point(S4950). In detail, the controller 1260 may calculate the initiationtime point of the thermoelectric operation for the thermal feedback bysubtracting the correction time from the thermal feedback sensing timepoint.

The content reproduction device 1200 may transmit a thermal feedbackinitiation signal at the initiation time point of the thermal operationfor the thermal feedback (S4960). When the thermoelectric operationinitiation time point is determined and a current reproduction time(hereinafter referred to as a reproduction time point) reaches theinitiation time point of the thermoelectric operation while the videocontent is reproduced, the controller 1260 may transmit the thermalfeedback initiation signal to the feedback device 1600 through thecommunication module 1220.

The feedback device 1600 may initiate a thermal feedback outputoperation according to the thermal feedback initiation signal (S4970).

FIG. 50 is a diagram showing a thermal feedback output operation of athermal experience providing method considering a reduced response timeaccording to an embodiment of the present invention.

In FIG. 50, FIG. 50A relates to a thermal feedback output operation whenthe reduced response time is not performed on the feedback device 1600,and FIG. 50B relates to a thermal feedback output operation when thereduced response time is considered in the feedback device 1600.

In detail, in FIG. 50B, the feedback device 1600 applies power to athermoelectric couple group at a time point at which the initiationsignal is received (which is substantially the same as a time point atwhich the thermoelectric operation is initiated). In this case, theinitiation signal reception time point considers a response time reducedthrough the thermal experience providing method described in FIG. 49.The thermoelectric couple group performs an exothermic operation orendothermic operation from a thermoelectric couple group powerapplication time point. When the correction time elapses from the powerapplication time point, the temperature of the contact surface 1641reaches a temperature at which a user may sense the thermal feedback.Accordingly, the user may sense the thermal feedback at a time point atwhich the thermal event scene is output after the multimedia content isreproduced.

Compared to FIG. 50A, the correction time in FIG. 50B may be shorterthan the correction time in FIG. 50A. This is because the delay time inFIG. 50B is shorter than the delay time in FIG. 50A. Also, although thedelay time is reduced, a time point at which the temperature of thecontact surface reaches the sensible temperature in FIG. 50A maycoincide with that in FIG. 50B because the reduced delay time isreflected in the correction time.

Accordingly, even when the thermal feedback response time reductionmethod is performed as shown in FIG. 50B, The feedback device 1600 maybe controlled by the content reproduction device 1200 to apply power toa thermoelectric element at the initiation time point of thethermoelectric operation, which is set to precede the output time pointof the specific scene to be linked to the thermal feedback. Thus, thethermoelectric operation may start to be performed, and a user may sensethe thermal feedback at the output time point of the specific scene.

Although the above description assumes that an image is synchronizedwith a thermal feedback, a voice may be synchronized with the thermalfeedback instead of the image. This may be easily understood by thoseskilled in the art by replacing the image data and the thermal eventscene with voice data and a thermal event voice.

FIG. 51 is a flowchart showing a thermal experience providing methodconsidering a reduced response time according to another embodiment ofthe present invention.

Referring to FIG. 51, the thermal experience providing methodconsidering the reduced response time may include acquiring thermalfeedback data (S5110), determining an initiation time point of a thermalfeedback in consideration of a reduced delay time of the thermalfeedback (S5120), and initiating a thermal feedback output operation atthe initiation time point of the thermal feedback (S5130).

The aforementioned steps of the embodiment will be described in detailbelow.

The feedback device 1600 may acquire thermal feedback data from thecontent reproduction device 1200 (S5110). The thermal feedback data mayinclude information regarding the types and intensities of thermalfeedbacks output from thermoelectric couple groups and the output starttimes and/or end times of the thermal feedbacks.

Also, the feedback device 1600 may determine an initiation time point ofa thermal feedback in consideration of a reduced delay time of thethermal feedback (S5120).

According to an embodiment of the present invention, when the thermalfeedback response time reduction method is performed on the feedbackdevice 1600, a delay time, which indicates a period from the initiationtime point of the thermal feedback up to a sensing time point at which auser senses the thermal feedback, may be reduced. In some cases, theoutput time point of the thermal feedback included in the thermalfeedback data may not reflect the delay time. In this case, when thethermal feedback is initiated according to the output time point of thethermal feedback included in the thermal feedback data, the user'ssensing time point may be advanced. Accordingly, the thermal event sceneand the thermal feedback may be out of synchronization to hinder theuser's experience. In order to solve such a problem, the feedback device1600 may determine the thermal feedback initiation time point on thebasis of the reduced delay time and the thermal feedback output timepoint included in the thermal feedback data.

As an example, information regarding the reduced delay time (or thereduced response time) may be prestored in the memory of the feedbackdevice 1600, and the feedback device may correct the thermal feedbackoutput time point included in the thermal feedback data on the basis ofthe information regarding the reduced delayed time and then determine athermal feedback initiation time point.

Also, the feedback device 1600 may initiate a thermal feedback outputoperation at the thermal feedback initiation time point (S5130). By thethermal feedback initiation time point being corrected by the feedbackdevice 1600 on the basis of the reduced delay time, the thermal eventscene may be synchronized with the thermal feedback, and thus the user'sexperience may be enhanced.

5. End Time Reduction Method for Thermal Feedback

An end time reduction method for a thermal feedback according to anembodiment of the present invention will be described below. Here, theend time may refer to the time it takes for the temperature of thecontact surface of the thermoelectric couple group which is changed bythe output of the thermal feedback to return to an initial temperaturewhen the thermal feedback ends. Also, the end time reduction method forthe thermal feedback may be understood as a method of reducing the endtime.

In detail, the thermoelectric couple group 1644 or the contact surface1641 has a predetermined heat capacity. Thus, when an exothermicoperation or endothermic operation is initiated by applying power to theheat output module 1640, the temperature of the contact surface 1641gradually changes from an initial temperature and reaches a saturationtemperature instead of reaching the saturation temperature as soon aspower is applied. On the other hand, when the exothermic operation orendothermic operation is stopped by shutting off the power, thetemperature of the contact surface 1641 gradually changes and returns tothe initial temperature instead of returning to the initial temperaturedirectly from the saturation temperature.

In this case, the user may feel an unnecessary heat sensation due to thetemperature of the contact surface 1641 gradually returning from thesaturation temperature to the initial temperature. For example, when ahot feedback with a fifth intensity is output from the heat outputmodule 1640, the saturation temperature of the contact surface 1641 mayincrease up to the saturation temperature of the hot feedback with thefifth intensity. When the output of the hot feedback ends, thetemperature of the contact surface 1641 may drop from the saturationtemperature of the hot feedback with the fifth intensity to the initialtemperature. In this case, as the temperature of the contact surface1641 drops gradually, the user unintentionally feels hot feedbacks withfirst to fourth intensities. The hot feedbacks with the first to fourthintensities are heat unnecessary for the user, and thus the user'sthermal experience is hindered.

However, in this case, by the feedback device 1600 performing the endtime reduction method for the thermal feedback, when the end time isreduced, the temperature of the contact surface 1641 reaches the initialtemperature within a short time after the thermoelectric operation ends.

Accordingly, as the end time is reduced, the user does not feel theunnecessary heat, and thus the user's thermal experience may beenhanced.

The end time reduction method for the thermal feedback will be describedbelow. Also, for convenience of description, the following descriptionassumes that the end time reduction method is performed by the feedbackdevice 1600. However, the present invention is not limited thereto, andthe end time reduction method may be performed by the contentreproduction device 1200 and may be performed by a third apparatus otherthan the feedback device 1600 and the content reproduction device 1200.

FIG. 52 is a flowchart showing an end time reduction method for athermal feedback according to an embodiment of the present invention.

Referring to FIG. 52, the end time reduction method may include checkingan output end time point of the thermal feedback (S5210) and applyingend power to a thermoelectric couple group during a predetermined timeafter the output end time point of the thermal feedback (S5220).

In detail, the feedback device 1600 may check the output end time pointof the thermal feedback (S5210). The type of the thermal feedback may beany one of a hot feedback, a cold feedback, or a thermal grill feedback.Also, the type (forward voltage/reverse voltage) and magnitude of avoltage applied to the thermoelectric couple group may be predeterminedaccording to the type and intensity of the thermal feedback.

According to an embodiment of the present invention, the feedback device1600 may acquire thermal feedback data from the content reproductiondevice 1200. The thermal feedback data may include information regardingthe types and intensities of thermal feedbacks output fromthermoelectric couple groups and the output start times and/or end timesof the thermal feedbacks. The feedback device 1600 may check the outputend time point of the thermal feedback output from the thermoelectriccouple group on the basis of the thermal feedback data.

Also, the feedback device 1600 may apply end power to the thermoelectriccouple group for a predetermined time after the output end time point ofthe thermal feedback (S5220).

In order to reduce the end time, which is the time it takes for thetemperature of the contact surface of the thermoelectric couple groupchanged by the output of the thermal feedback to return to an initialtemperature, the feedback device 1600 may apply end power during apredetermined time after the output end time point of the thermalfeedback instead of stopping the application of the power for outputtingthe thermal feedback. Here, the end power may refer to power applied toreduce the time it takes for the temperature of the contact surface toreach the initial temperature when the output of the thermal feedbackends (hereinafter, the voltage and current of the end power are referredto as a “end voltage” and a “end current”). Also, the end power may bein the opposite direction to power (hereinafter referred to as“operating power”) applied to output the thermal feedback (hereinafter,the voltage and current of the operating power are referred to as an“operating voltage” and an “operating current”). For example, the endvoltage may be a reverse voltage when the operating voltage is a forwardvoltage, and the end voltage may be a forward voltage when the operatingvoltage is a reverse voltage.

As the feedback device 1600 applies the end power to the thermoelectriccouple group during a predetermined time after the output end time pointof the thermal feedback, the temperature of the contact surface mayreach the initial temperature at an earlier time, and thus the end timemay be reduced. Also, the feedback device 1600 may stop the applicationof the end power after the predetermined time elapses.

However, the magnitude of the end power applied to reduce the end time,the application time (i.e., the predetermined time) of the end power,and the like may differ depending on various situations, for example,the type and intensity of the thermal feedback output from thethermoelectric couple group.

Implementations of the end time reduction method for the thermalfeedback in the various situations will be described below. Also, forconvenience of description, the following description focuses on a casein which a hot feedback is to be output from the thermoelectric couplegroup. However, the present invention is not limited thereto, and itwill be appreciated that the following description may be applied tocases in which a cold feedback or a thermal grill feedback is to beoutput from the thermoelectric couple group.

5.1. Implementation of End Time Reduction Method for Thermal Feedback

FIG. 53 is a diagram showing a change in temperature on a contactsurface and a change in applied voltage according to the end timereduction method for the thermal feedback when a hot feedback is outputfrom a thermoelectric couple group according to an embodiment of thepresent invention.

Referring to FIG. 53, the feedback device 1600 may apply, to thethermoelectric couple group, an operating voltage (a first forwardvoltage in the example of FIG. 53) for outputting the hot feedback.Accordingly, the temperature of the contact surface of thethermoelectric couple group may become a saturation temperature. Also,the feedback device 1600 may confirm that an output stop time point ofthe hot feedback is a first time point and may stop the application ofthe first forward voltage at the first time point in order to stopoutputting the hot feedback. Accordingly, the temperature of the contactsurface may drop from the saturation temperature along a first referencetemperature curve 5310 to gradually reach the initial temperature. Inthis case, the period from the first time point to the time point atwhich the temperature of the contact surface reaches the initialtemperature may be an end time for the thermal feedback (hereinafterreferred to as a first end time).

According to an embodiment of the present invention, the feedback device1600 may perform the thermal feedback end time reduction method in orderto reduce the end time. In detail, the feedback device 1600 may apply anend voltage (a first reverse voltage in the example of FIG. 53) betweenthe first time point, which is the thermal feedback output end timepoint, and a predetermined second time point. In this case, the endvoltage may be in the opposite direction to the operating voltage. Asthe end voltage is applied between the first time point and the secondtime point, the temperature of the contact surface may drop along asecond reference temperature curve 5320. As the temperature of thecontact surface drops along the second reference temperature curve 5320,a temperature drop rate of the contact surface when the end voltage isapplied to the thermoelectric couple group may be faster than atemperature drop rate of the contact surface when the end voltage is notapplied to the thermoelectric couple group between the first time pointand the second time point. In this case, the period from the first timepoint to the time point at which the temperature of the contact surfacereaches the initial temperature may be an end time for the thermalfeedback (hereinafter referred to as a second end time), and the secondend time may be shorter than the first end time. As a result, when thefeedback device 1600 performs the thermal feedback end time reductionmethod, the end time of the thermal feedback may be reduced by a timedifference between the first end time and the second end time.Accordingly, as the end time is reduced, the user does not feel theunnecessary heat caused by the end of the thermal feedback such that theuser's thermal experience may be enhanced.

According to an embodiment of the present invention, the magnitude ofthe end voltage may be predetermined. For example, as shown in theexample of FIG. 53, the intensity of the end voltage may be the same as,or higher or lower than, that of the operating voltage. However, the endvoltage may be in the opposite direction to the operating voltage.

According to an embodiment of the present invention, the feedback device1600 may determine the magnitude of the end voltage so that a thresholdtemperature does not exceed an initial temperature. This is because whenthe threshold temperature exceeds the initial temperature, the user maymisunderstand that a thermal feedback other than a previous thermalfeedback is output. According to an embodiment, the feedback device 1600may determine the magnitude of the end voltage so that the temperatureof the contact surface does not reach the initial temperature while theend voltage is applied. When the temperature of the contact surface doesnot reach the initial temperature while the end voltage is applied, thetemperature of the contact surface does not exceed the initialtemperature after the application of the end voltage ends.

Also, according to an embodiment of the present invention, the endvoltage may be determined depending on the intensity of the thermalfeedback, that is, the magnitude of the operating voltage. For example,since the intensity of the thermal feedback is a second intensity, theend voltage may be a second reverse voltage when the magnitude of theoperating voltage is a second forward voltage. Also, when the intensityof the thermal feedback is a third intensity, the intensity of theoperating voltage is a third forward voltage higher than the secondforward voltage, and the intensity of the end voltage may be a thirdreverse voltage higher than the second reverse voltage. On the otherhand, when the intensity of the thermal feedback is a first intensity,the intensity of the operating voltage is a first forward voltage lowerthan the second forward voltage, and the intensity of the end voltagemay be a first reverse voltage lower than the second reverse voltage.

Also, according to an embodiment, the end voltage may be predeterminedirrespective of the intensity of the thermal feedback.

Also, according to an embodiment of the present invention, the timepoint at which the application of the end voltage is stopped may bepredetermined. According to an embodiment of the present invention, thetime point at which the application of the end voltage is stopped may bedetermined depending on a threshold temperature indicating thetemperature of the contact surface at the second time point. That is,the time point at which the application of the end voltage is stoppedaffects the threshold temperature, and thus the time point at which theapplication of the end voltage is stopped may be predetermined inconsideration of a relation between the threshold temperature and thetime point at which the application of the end voltage is stopped. Forexample, the feedback device 1600 may stop applying the end voltage whenthe temperature of the contact surface 1641 reaches a predeterminedthreshold temperature.

Also, the time point at which the application of the end voltage isstopped (i.e., a time at which the end voltage is applied) may bedetermined as a time point before the threshold temperature reaches theinitial temperature. As described above, this is because when thethreshold temperature exceeds the initial temperature, the user maymisunderstand that a thermal feedback other than a previously outputthermal feedback is output. Accordingly, the feedback device 1600 maydetermine the time point at which the application of the end voltage isstopped so that the threshold temperature does not exceed the initialtemperature. According to an embodiment, the feedback device 1600 maydetermine the time point at which the application of the end voltage isstopped so that the temperature of the contact surface does not reachthe initial temperature while the end voltage is applied. When thetemperature of the contact surface does not reach the initialtemperature while the end voltage is applied, the temperature of thecontact surface does not exceed the initial temperature after theapplication of the end voltage ends.

Also, according to another embodiment of the present invention, the timepoint at which the application of the end voltage is stopped may bedetermined on the basis of the intensity of the thermal feedback. Forexample, the time point at which the application of the end voltage isstopped may be t seconds when the intensity of the thermal feedback isthe first intensity and may be t+a seconds (or t−a seconds) when theintensity of the thermal feedback is the second intensity.

Also, according to an embodiment of the present invention, whether toapply the end voltage to the thermoelectric couple group may bedetermined depending on the intensity of the thermal feedback, that is,the magnitude of the operating voltage. For example, when the intensityof the thermal feedback is lower than a predetermined intensity, thetemperature of the contact surface may quickly reach the initialtemperature although the end voltage is not applied. In this case, theeffect of reducing the end time according to the application of the endvoltage is small. Thus, when the intensity of the thermal feedback islower than the predetermined intensity, the feedback device 1600 may notapply the end voltage. Likewise, when the intensity of the thermalfeedback is higher than the predetermined intensity, the feedback device1600 may apply the end voltage to the thermoelectric couple group inorder to reduce the end time because the effect of reducing the end timeaccording to the application of the end voltage is large.

FIG. 54 is a diagram showing a change in temperature on a contactsurface and a change in applied voltage according to the end timereduction method for the thermal feedback when a hot feedback is outputfrom a thermoelectric couple group according to another embodiment ofthe present invention.

Referring to FIG. 54, the feedback device 1600 may apply, to thethermoelectric couple group, an operating voltage (a first forwardvoltage in the example of FIG. 54) for outputting the hot feedback andthen may stop applying the operating voltage at a first time point,which is a time point at which the output of the hot feedback isstopped. Accordingly, the temperature of the contact surface may dropfrom a saturation temperature along a first reference temperature curve5410 to reach an initial temperature after a first end time elapses.

Also, according to an embodiment of the present invention, the feedbackdevice 1600 may apply a first end voltage (a first reverse voltage inthe example of FIG. 54) between a first time point and a second timepoint. As the first end voltage is applied, the temperature of thecontact surface may drop along a second reference temperature curve 5420between the first time point and the second time point. As thetemperature of the contact surface drops along the second referencetemperature curve 5420, the temperature of the contact surface may reachthe initial temperature after a second end time, which is shorter thanthe first end time, elapses.

Also, according to an embodiment of the present invention, the feedbackdevice 1600 may apply a second end voltage (a second reverse voltage inthe example of FIG. 54) higher than the first end voltage between thefirst time point and the second time point. As the second end voltage isapplied between the first time point and the second time point, thetemperature of the contact surface may drop along a third referencetemperature curve 5430. Accordingly, the temperature of the contactsurface may reach the initial temperature after a third end time, whichis shorter than the second end time, elapses.

In summary, as the magnitude of the end voltage increases, the end timeof the thermal feedback may be reduced. Thus, the user may not feelunnecessary heat caused by the end of the thermal feedback.

However, when the magnitude of the end voltage increases over apredetermined critical voltage, the temperature of the contact surfacemay be lower than the initial temperature. When the temperature of thecontact surface is lower than the initial temperature, the user may feelan unnecessary cold sensation. Thus, the feedback device 1600 may adjustthe magnitude of the end voltage so that the temperature of the contactsurface of the thermoelectric couple group does not fall below theinitial temperature.

FIG. 55 is a diagram showing a change in temperature on a contactsurface and a change in applied voltage according to the end timereduction method for the thermal feedback when a hot feedback is outputfrom a thermoelectric couple group according to still another embodimentof the present invention.

Referring to FIG. 55, the feedback device 1600 may apply, to thethermoelectric couple group, an operating voltage (a first forwardvoltage in the example of FIG. 55) for outputting the hot feedback andthen may stop applying the operating voltage at a first time point,which is a time point at which the output of the hot feedback isstopped. Accordingly, the temperature of the contact surface may dropfrom a saturation temperature along a first reference temperature curve5510 to reach an initial temperature after a first end time elapses.

Also, according to an embodiment of the present invention, the feedbackdevice 1600 may apply the end voltage (a first reverse voltage in theexample of FIG. 55) between a first time point and a second time point.As the end voltage is applied, the temperature of the contact surfacemay drop along a second reference temperature curve 5520 between thefirst time point and the second time point. As the temperature of thecontact surface drops along the second reference temperature curve 5520,the temperature of the contact surface may reach the initial temperatureafter a second end time, which is shorter than the first end time,elapses.

Also, according to an embodiment of the present invention, the feedbackdevice 1600 may apply the end voltage from the first time point up to athird time point. As the end voltage is applied up to the third timepoint, which is after the second time point, the temperature of thecontact surface may drop along a second reference temperature curve 5520from the first time point up to the third time point through the secondtime point. Accordingly, the temperature of the contact surface mayreach the initial temperature after the third end time, which is shorterthan the second end time, elapses.

In summary, as the time during which the end voltage is appliedincreases, the end time of the thermal feedback may be reduced. Thus,the user may not feel unnecessary heat caused by the end of the thermalfeedback.

However, when the time during which the end voltage is applied exceeds apredetermined critical time, the temperature of the contact surface ofthe thermoelectric couple group may decrease below the initialtemperature. According to an embodiment of the present invention, thefeedback device 1600 may adjust the time during which the end voltage isapplied so that the temperature of the contact surface of thethermoelectric couple group does not fall below the initial temperature.

FIG. 56 is a diagram showing a change in temperature on a contactsurface and a change in applied voltage according to the end timereduction method for the thermal feedback when a cold feedback is outputfrom a thermoelectric couple group according to an embodiment of thepresent invention.

Referring to FIG. 56, the feedback device 1600 may apply, to thethermoelectric couple group, an operating voltage (a first reversevoltage in the example of FIG. 56) for outputting the cold feedback andthen may stop applying the operating voltage at a first time point,which is a time point at which the output of the cold feedback isstopped. Accordingly, the temperature of the contact surface may risefrom a saturation temperature along a first reference temperature curve5610 to reach an initial temperature after a first end time elapses.

As is the case in which a hot feedback is output from a thermoelectriccouple group, the feedback device 1600 may apply an end voltage (a firstforward voltage in the example of FIG. 56) between the first time pointand a second time point by using the thermal feedback end time reductionmethod.

As the end voltage is applied, the temperature of the contact surface ofthe thermoelectric couple group may rise along a second referencetemperature curve 5620 between the first time point and the second timepoint at a rate faster than a temperature rise rate of the contactsurface when the end voltage is not applied to the thermoelectric couplegroup. As the temperature of the contact surface rises along the secondreference temperature curve 5620, the temperature of the contact surfacemay reach the initial temperature after a second end time, which isshorter than the first end time, elapses. Thus, the cold feedback maymore earlier ends by a reduction time, which is a difference between thefirst end time and the second end time.

According to an embodiment of the present invention, the magnitude ofthe end voltage may be predetermined, and the time point at which theapplication of the end voltage is stopped, that is, the time point atwhich the operating voltage is applied, may be predetermined.

Also, according to an embodiment of the present invention, a large endvoltage may be applied at the first time point in order to furtherreduce the end time. The description with reference to FIGS. 53 to 55may be applied to various implementations as it is, and thus a detaileddescription thereof will be omitted.

FIG. 57 is a diagram showing a change in temperature on a contactsurface and a change in applied voltage according to the end timereduction method for the thermal feedback when a thermal grill feedbackis output from a thermoelectric couple group according to an embodimentof the present invention.

Referring to FIG. 57, a thermal grill feedback with a first intensitymay be output from a first thermoelectric couple group and a secondthermoelectric couple group in the feedback device 1600. When theneutral ratio is set to 2, the feedback device 1600 may apply, to thefirst thermoelectric couple group, a first operating voltage (a firstforward voltage in the example of FIG. 57) for outputting a hot feedbackwith a first intensity and may apply, to the second thermoelectriccouple group, a first operating voltage (a second reverse voltage in theexample of FIG. 57) for outputting a cold feedback with a secondintensity. Thus, the temperature of the contact surface of the firstthermoelectric couple group may reach a first saturation temperature,and the temperature of the contact surface of the second thermoelectriccouple group may reach a second-prime saturation temperature.

Also, when the output of the thermal grill feedback ends at a first timepoint, the feedback device 1600 may stop applying the first operatingvoltage and the second operating voltage at the first time point.Accordingly, the temperature of the surface area of the firstthermoelectric couple group may drop along a first reference temperatureintensity 5710, and the temperature of the surface area of the secondthermoelectric couple group may rise along a third reference temperatureintensity 5730 so that the temperature of the surface area of the firstthermoelectric couple group and the temperature of the surface area ofthe second thermoelectric couple group may reach an initial temperatureafter a first end time elapses.

Also, by using the thermal feedback end time reduction method, thefeedback device 1600 may apply, to the first thermoelectric couplegroup, a first end voltage (a first reverse voltage in the example ofFIG. 57) for stopping output of the hot feedback with the firstintensity and may apply, to the second thermoelectric couple group, asecond end voltage (a second forward voltage in the example of FIG. 57)for stopping output of the cold feedback with the second intensity,between the first time point and a second time point.

Since the first end voltage is applied to the first thermoelectriccouple group, the temperature of the contact surface of the firstthermoelectric couple group may drop along a second referencetemperature curve 5720 at a rate faster than a temperature drop rate ofthe contact surface when the first end voltage is not applied to thefirst thermoelectric couple group. Also, since the second end voltage isapplied to the second thermoelectric couple group, the temperature ofthe contact surface of the second thermoelectric couple group may risealong a fourth reference temperature curve 5740 at a rate faster than atemperature rise rate of the contact surface when the second end voltageis not applied to the second thermoelectric couple group. Accordingly,the temperature of the contact surface of the first thermoelectriccouple group and the temperature of the contact surface of the secondthermoelectric couple group may reach the initial temperature at asecond end time shorter than the first end time.

However, for convenience of description, it is assumed that a time pointat which the temperature of the contact surface of the firstthermoelectric couple group reaches the initial temperature and a timepoint at which the temperature of the contact surface of the secondthermoelectric couple group reaches the initial temperature coincidewith each other, but the present invention is not limited thereto. Thetime point at which the temperature of the contact surface of the firstthermoelectric couple group reaches the initial temperature and the timepoint at which the temperature of the contact surface of the secondthermoelectric couple group reaches the initial temperature may notcoincide with each other. For example, in order for the cold feedback tobe output from the second thermoelectric couple group, when electricenergy is applied to the second thermoelectric couple group, a part ofthe electric energy induces an endothermic reaction while the remainingpart of the electric energy is converted into heat energy. Here, thepart directly converted into the heat energy is discharged through aheat sink or the like connected to the rear surface of thethermoelectric element, but a part thereof remains in the thermoelectricelement in the form of residual heat. In some cases, due to the residualheat, the temperature of the contact surface of the secondthermoelectric couple group may reach the initial temperature fasterthan the temperature of the contact surface of the first thermoelectriccouple group.

As another example, a difference between the initial temperature and thesecond-prime saturation temperature may be greater than a differencebetween the initial temperature and the first saturation temperature. Insome cases, due to the temperature difference, the temperature of thecontact surface of the first thermoelectric couple group may reach theinitial temperature faster than the temperature of the contact surfaceof the second thermoelectric couple group.

As described above, when the end time reduction method for the thermalfeedback is performed on the feedback device 1600 although thetemperature of the contact surface of the first thermoelectric couplegroup and the temperature of the contact surface of the secondthermoelectric couple group reach the initial temperature at differenttime points, the time it takes for the temperature of the contactsurface of the first thermoelectric couple group to reach the initialtemperature and the time it takes for the temperature of the contactsurface of the second thermoelectric couple group to reach the initialtemperature are reduced. That is, as the time point at which the outputof the thermal grill feedback ends is reduced, the user may not feelunnecessary heat.

5.2. Continuous Output of Thermal Feedback

FIG. 58 is a diagram showing a change in temperature on a contactsurface and a change in applied voltage when a hot feedback iscontinuously output from a thermoelectric couple group according to anembodiment of the present invention.

Referring to FIG. 58, FIG. 58A relates to a continuous hot feedbackoutput operation when the thermal feedback end time reduction method isnot performed. In FIG. 58A, the feedback device 1600 may acquire thermalfeedback data from the content reproduction device 1200 and may apply anoperating voltage (a first forward voltage in FIG. 58) to athermoelectric couple group up to a first time point according to thethermal feedback data. Accordingly, the temperature of the contactsurface of the thermoelectric couple group may become a saturationtemperature. Also, according to the thermal feedback data, the feedbackdevice 1600 may stop applying the operating voltage at the first timepoint, and the temperature of the contact surface may drop during afirst response time and reach the initial temperature at a first endtime point. In this case, according to the thermal feedback data, thefeedback device 1600 may apply the operating voltage to thethermoelectric couple group in order to output a second hot feedback ata third time point. When the temperature of the contact surface at thethird time point is the initial temperature and the operating voltage isapplied to the thermoelectric couple group, the temperature of thecontact surface may be saturated at a first saturation time point.However, in FIG. 58A, the third time point is a time point preceding thefirst end time point, and the temperature of the contact surface at thethird time point may be higher than the initial temperature. Thus, whenthe operating voltage is applied to the thermoelectric couple group atthe third time point, the temperature of the contact surface may reachthe saturation temperature at a second saturation time point, which isbefore the first saturation time point. Also, as the time it takes toreach the saturation temperature is reduced, a time point at which theuser senses the thermal feedback through the contact surface may precedethe user's sensing time point intended by the content reproductiondevice 1200.

According to an embodiment of the present invention, the user's sensingtime point intended by the content reproduction device 1200 has tocoincide with the time point at which the user senses the thermalfeedback through the contact surface. The user's intended sensing timepoint may coincide with a thermal event scene reproduction time point.Thus, when the user's sensing time point does not coincide with the timepoint at which the user senses the thermal feedback through the contactsurface, the thermal event scene reproduction time point and the timepoint at which the user senses the thermal feedback through the contactsurface are out of synchronization, and thus the user's thermalexperience may be degraded.

Accordingly, in FIG. 58A, since the time point at which the user sensesthe thermal feedback through the contact surface precedes the user'sintended sensing time point, the user's thermal experience may bedegraded.

FIG. 58B relates to a continuous hot feedback output operation when thethermal feedback end time reduction method is performed. In FIG. 58B,the feedback device 1600 may acquire thermal feedback data from thecontent reproduction device 1200 and may apply an operating voltage (afirst forward voltage in FIG. 58) to a thermoelectric couple group up toa first time point according to the thermal feedback data. Also,according to the thermal feedback data, the feedback device 1600 mayapply the end voltage (a first reverse voltage in FIG. 58) between thefirst time point and a second time point. Accordingly, the temperatureof the contact surface may drop during a second response time and mayreach the initial temperature at a second end time point, which isbefore the first end time point.

In this case, as in FIG. 58A, according to the thermal feedback data,the feedback device 1600 may apply the operating voltage to thethermoelectric couple group in order to output a second hot feedback ata third time point. However, unlike FIG. 58A, the temperature of thecontact surface may be the initial temperature at the third time point.Thus, the temperature of the contact surface may be saturated at thefirst saturation time point by the operating voltage. That is, unlikeFIG. 58A, the time it takes to reach the saturation temperature may notbe reduced. Accordingly, the time point at which the user senses thethermal feedback through the contact surface may not be reduced. As aresult, the user's sensing time point intended by the contentreproduction device 1200 may coincide with the time point at which theuser senses the thermal feedback through the contact surface.

Since the user's intended sensing time point may coincide with thethermal event scene reproduction time point, the thermal event scenereproduction time point may coincide with the time point at which theuser senses the thermal feedback through the contact surface, and thusthe user's thermal experience may not be degraded.

In summary, the end time of the first thermal feedback is reduced by theend time reduction method for the thermal feedback, and thus the outputof a subsequent second thermal feedback may be more earlier initiated.In FIG. 58A, in order to not degrade the user's thermal experience, theoutput of the second thermal feedback should be initiated after thefirst end time point. On the other hand, in FIG. 58B, the user's thermalexperience may not be degraded although the output of the second thermalfeedback is initiated after a second end time point, which precedes thefirst end time point.

Accordingly, when the thermal feedback end time reduction method isperformed, it is possible to continuously output a thermal feedback in ashorter time.

6. Feedback Device with Enhanced Waste Heat Dissipation Performance andEnhanced Cold Sensation Provision Performance

FIG. 59 is a block diagram showing a configuration of the feedbackdevice 1600 according to another embodiment of the present invention.

Referring to FIG. 59, as described above, the feedback device 1600 mayinclude a heat output module 1640, a heat dissipation unit 2000, aliquid provision unit 3000, and a heat buffer material 4000. Here, theheat buffer material 4000 may indicate a material that absorbs apredetermined amount of heat from the outside of the heat buffermaterial 4000 and holds the absorbed heat.

The heat output module 1640 may output a thermal feedback. The thermalfeedback may be output by the heat output module 1640, which includes acontact surface 1641 brought into contact with a user's body and athermoelectric element connected to the contact surface 1641, applyinghot heat or cold heat, which is generated in the thermoelectric elementwhen power is applied, to the user's body through the contact surface1641. According to an embodiment of the present invention, the heatoutput module 1640 may perform an exothermic operation, endothermicoperation, or thermal grill operation according to a thermal feedbacksignal received from an external device through a communication module(not shown) for communicating with the external device, instead of thefeedback device 1600, to output a thermal feedback, and the user mayexperience a thermal experience due to the output thermal feedback.Also, when a temperature difference occurs near the heat output module1640, an electromotive force may be generated, and the heat outputmodule 1640 may provide electric power using the electromotive force.

The heat dissipation unit 2000 may be configured to dissipate waste heatgenerated by the thermoelectric module 1000 to the outside of thefeedback device 1600. Here, the waste heat may refer to the remainingheat other than heat used to provide a thermal experience to the useramong the heat generated by the feedback device 1600. For example,residual heat remaining in the feedback device 1600 after the thermalfeedback is output by the heat output module 1640 may be included in thewaste heat.

The liquid provision unit 3000 may be configured to allow the heatdissipation unit 2000 to dissipate the waste heat in the form of latentheat. According to an embodiment of the present invention, the liquidprovision unit 3000 may provide liquid to the heat dissipation unit2000, and the liquid provided by the heat dissipation unit 2000 may bevaporized by the waste heat delivered from the heat output module 1640.Due to the vaporization, a larger amount of waste heat may be dischargedto the outside. Also, the temperature of the feedback device 1600 maydrop due to the vaporization. For example, the vaporized liquid may takeheat away from liquid that is provided to the heat dissipation unit 2000but is not vaporized, and thus the temperature of the liquid that isprovided to the heat dissipation unit 2000 but is not vaporized maydecrease.

As the heat buffer material 4000 absorbs and holds a predeterminedamount of heat, the degree to which the user's thermal experience isdegraded by the waste heat may decrease, and the amount of cold heattransferred to the user may increase while waste heat absorbed by theheat buffer material 4000 is additionally generated.

According to an embodiment of the present invention, the heat buffermaterial 4000 may be provided in various shapes. For example, the heatbuffer material 4000 may be provided in an independent material shape.As an example, the heat buffer material 4000 may be disposed in apartial region of the heat dissipation unit 2000 in a plurality ofindependent material shapes. As another example, the heat buffermaterial 4000 may be provided in the form of a layer. As an example, theheat buffer material 4000 may be disposed on one surface of at least oneof the heat output module 1640, the heat dissipation unit 2000, or theliquid provision unit 3000 in the form of a layer.

It will be appreciated that the heat buffer material 4000 may beprovided in any form capable of being included in the feedback device1600 other than the independent material shape or layer shape. Also,according to an embodiment, the heat buffer material 4000 may beseparated from the feedback device 1600. As an example, the heat buffermaterial 4000 may be separated from the feedback device 1600 andreplaced with another heat buffer material. As another example, when theheat buffer material 4000 absorbs heat, the heat buffer material 4000may be separated from the feedback device 1600 so that the heat isdissipated to the outside of the feedback device 1600.

According to an embodiment of the present invention, the heat buffermaterial 4000 may be a phase change material (PCM). The PCM, which is amaterial with high heat of fusion, may be melted or solidified atspecific temperatures to store or release a large amount of heat energy.In an embodiment, the PCM may store or release heat through chemicalbonding. As an example, it is assumed that the PCM is a solid-to-liquidphase transition material. When heat is applied while the PCM is solid,the temperature of the PCM increases. When the temperature of the PCMreaches the melting point or the transition temperature of the PCM, thePCM continues to absorb heat, but the temperature of the PCM does notincrease. In this case, the PCM transitions from solid to liquid.Subsequently, when heat is not applied to the PCM, the PCM releases theaccumulated heat to the outside so that the PCM may return from liquidto solid. Thus, the temperature of the PCM increases from the initialtemperature to the transition temperature but does not increase untilthe phase transition is completed after the transition temperature isreached. Also, each PCM may have an inherent transition temperature.When the PCM is composed of the heat buffer material 4000, thetransition temperature of the PCM may fall within an internaltemperature change range of the feedback device 1600. When thetransition temperature of the PCM is not within the internal temperaturechange range of the feedback device 1600, the phase transition of thePCM does not occur although waste heat is accumulated in the feedbackdevice 1600. Accordingly, the temperature of the PCM continuouslyincreases, and thus the PCM cannot function as the heat buffer material4000. For example, the transition temperature of the PCM may rangebetween 5° C. and 60° C. or between 20° C. and 40° C.

According to an embodiment of the present invention, a PCM used for theheat buffer material 4000 may be composed of various materials. Forexample, the PCM may include hydrated inorganic salts including hydratedcalcium chloride, lithium nitrogen oxide, glauber's salt, and the like;polyhydric alcohols including dimethyl propanediol (DMP), hexamethylpropanediol (HMP), xylitol, erythritol, and the like; and linear chainhydrocarbons including a polyethylene terephthalate (PET)-polyethyleneglycol (PEG) copolymer, PEG, polytetramethyl glycol (PTMG), andparaffin.

Also, according to an embodiment of the present invention, a PCM usedfor the heat buffer material 4000 may be implemented in various forms.For example, the PCM may be included in a microcapsule, filled infabric, or coated.

FIG. 60 is a diagram showing a structure of the feedback deviceaccording to an embodiment of the present invention.

FIG. 60 shows a cross-sectional view of the feedback device 1600according to an embodiment of the present invention. Referring to FIG.60, the feedback device 1600 may be stacked in the order of the heatoutput module 1640 and the heat dissipation unit 2000, and the liquidprovision unit 3000 may be placed inside the heat dissipation unit 2000.Here, the heat output module 1640 may have a bottom surface in direct orindirect contact with a user to provide a thermal feedback to the user.For example, it is assumed that the feedback device is a wrist band typewearable device. When the wearable device is worn by a user, the heatoutput module 1640 may be placed at a portion in contact with the user,and the heat dissipation unit 2000 may be placed at a portion not incontact with the user. Also, a part to which waste heat is transferredfrom the heat dissipation unit 2000 may be a heat transfer unit 2100(e.g., the bottom surface and a side surface of the heat dissipationunit 2000), and a part in which waste heat is evaporated in the form oflatent heat may be a heat radiating unit 2200 (e.g., the top surface ofthe heat dissipation unit 2000).

In addition, according to an example embodiment of the presentinvention, a liquid blocking material (e.g., a waterproof membrane, awaterproof film) may be disposed between the liquid provision unit 3000and the heat output module 1640 so that liquid may be prevented frombeing transferred from the liquid provision unit 3000 to the heat outputmodule 1640.

According to an embodiment of the present invention, when the heatoutput module 1640 performs an endothermic operation, cold heat may betransferred to the bottom surface of the heat output module 1640, andhot heat may be transferred to the top surface of the thermoelectricmodule 1000. Such a hot heat may be waste heat that may degrade a user'sthermal experience. In this case, the waste heat may be transferred fromthe thermoelectric module 1000 to the heat radiating unit 2200 throughthe heat transfer unit 2100 and the liquid provision unit 3000 and maybe discharged by the heat radiating unit 2200. That is, a waste heattransfer path may be formed using the heat output module 1640, the heattransfer unit 2100, the liquid provision unit 3000, and the heatradiating unit 2200. In this case, the liquid provision unit 3000 mayprovide liquid contained in the liquid provision unit 3000 to the heatradiating unit 2200, and the liquid provided by the liquid provisionunit 3000 may be evaporated in the heat radiating unit 2200 due to thewaste heat. Due to the evaporation of the liquid, the waste heat may bedischarged to the outside of the feedback device 1600.

Also, according to an embodiment of the present invention, the heatradiating unit 2200 may have liquid transfer directionality in aspecific direction for each material. For example, the liquid transferdirectionality of the heat radiating unit 2200 may be vertical orhorizontal. According to an embodiment of the present invention, liquidmay be transferred from the bottom of the heat radiating unit 2200 tothe heat radiating unit 2200. Thus, according to an embodiment of thepresent invention, it may be advantageous, in terms of improving wasteheat dissipation performance, for the heat radiating unit 2200 to havethe vertical liquid transfer directionality.

Also, according to an embodiment of the present invention, the heatradiating unit 2200 may have evaporation directionality in a specificdirection for each material. For example, the evaporation directionalityof the heat radiating unit 2200 may be an upward direction or a lateraldirection. According to an embodiment of the present invention, liquidmay evaporate into the air on the top of the heat radiating unit 2200.Thus, according to an embodiment of the present invention, it may beadvantageous, in terms of improving waste heat dissipation performance,for the heat radiating unit 2200 to have the upward evaporationdirectionality.

Also, in a structure according to an embodiment of the presentinvention, the length of the waste heat transfer path may vary dependingon the thickness of the liquid provision unit 3000. For example, in theexample of FIG. 60, a waste heat transfer path when the thickness of theliquid provision unit 3000 is “b” may be shorter than a waste heattransfer path when the thickness of the liquid provision unit 3000 is“a.” As the waste heat transfer path is reduced, a time during which thewaste heat remains in the liquid provision unit 3000 may be shortened,and thus the waste heat dissipation performance of the feedback device1600 may be enhanced.

In an embodiment, when the thickness of the liquid provision unit 3000decreases, the amount of liquid contained by the liquid provision unit3000 may decrease. When no liquid remains in the liquid provision unit3000, liquid has to be replenished. As the thickness of the liquidprovision unit 3000 decreases, the time it takes to deplete liquid mayalso decrease. That is, depending on the thickness of the liquidprovision unit 3000, the waste heat dissipation performance of thefeedback device 1600 and the liquid holding performance of the liquidprovision unit 3000 may be in a trade-off relationship.

FIG. 61 is a diagram showing a structure of the feedback device to whicha heat buffer material is applied according to an embodiment of thepresent invention.

Referring to FIG. 61, the feedback device 1600 may be stacked in theorder of the heat output module 1640 and the heat dissipation unit 2000,and the liquid provision unit 3000 may be placed inside the heatdissipation unit 2000. In this case, the heat buffer material 4000 maybe placed between the heat dissipation unit 2000 and the heat outputmodule 1640. Here, the heat buffer material 4000 may be implemented inthe form of a layer. Also, the heat dissipation unit 2000 may becomposed of a heat transfer unit 2100 and a heat radiating unit 2200.Also, a waste heat transfer path may be formed using the heat outputmodule 1640, the heat buffer material 4000, the heat transfer unit 2100,the liquid provision unit 3000, and the heat radiating unit 2200.

According to an embodiment of the present invention, as the heat buffermaterial 4000 is placed between the heat output module 1640 and the heattransfer unit 2100, the amount of waste heat accumulated inside thefeedback device 1600 during a predetermined time may decrease, and thetransfer of the waste heat from the heat output module 1640 to the heattransfer unit 2100 may be delayed. As a specific example, when the heatoutput module 1640 performs an endothermic operation, waste heat may begenerated in the heat output module 1640. Also, when the generated wasteheat is transferred to the heat buffer material 4000, the temperature ofthe heat buffer material 4000 increases up to a transition temperaturedue to the waste heat, but the temperature of the heat buffer material4000 may be maintained at the transition temperature until the phasetransition of the heat buffer material 4000 is completed. In this case,while the temperature of the heat buffer material 4000 is maintained atthe transition temperature, the waste heat is not accumulated inside thefeedback device 1600 because the heat buffer material 4000 absorbs thewaste heat. Also, the waste heat, which has a temperature higher thanthe transition temperature, may not be transferred from the heat buffermaterial 4000 to the heat transfer unit 2100. Subsequently, when thephase transition of the heat buffer material 4000 is completed, wasteheat having a temperature higher than the transition temperature isadditionally accumulated inside the feedback device 1600, and the wasteheat may be transferred to the heat transfer unit 2100. Thus, while theheat buffer material 4000 is maintained at the transition temperature,the amount of waste heat inside the feedback device 1600 is reducedcompared to the case where the heat buffer material 4000 is notincluded. As the effect of the waste heat on the user's thermalexperience is reduced while the heat buffer material 4000 is maintainedat the transition temperature, cold sensation provision performance ofthe feedback device 1600 may be enhanced.

The method according to an embodiment may be implemented as programinstructions executable by a variety of computers and may be recorded ona computer-readable medium. The computer-readable recording medium mayinclude a program instruction, a data file, a data structure, or acombination thereof. The program instruction recorded in the medium maybe designed and configured specially for the embodiment or may bepublicly known and available to those skilled in the field of computersoftware. Examples of the computer-readable recording medium include amagnetic medium, such as a hard disk, a floppy disk, and a magnetictape, an optical medium, such as a compact disc read-only memory(CD-ROM), a digital versatile disc (DVD), etc., a magneto-optical mediumsuch as a floptical disk, and a hardware device specially configured tostore and perform program instructions, for example, a read-only memory(ROM), a random access memory (RAM), a flash memory, etc. Examples ofthe program instructions include not only machine code generated by acompiler or the like but also high-level language codes that may beexecuted by a computer using an interpreter or the like. The hardwaredevice may be configured as at least one software module in order toperform operations of the embodiment and vice versa.

Although the present invention has been described with reference tospecific embodiments and features, it will be appreciated that variousvariations and modifications can be made from the invention by thoseskilled in the art. For example, suitable results may be achieved if thedescribed techniques are performed in a different order and/or ifcomponents in a described system, architecture, device, or circuit arecombined in a different manner and/or replaced or supplemented by othercomponents or their equivalents.

Accordingly, other implementations, embodiments, and equivalents arewithin the scope of the following claims.

The invention claimed is:
 1. A method for providing a thermal feedbackto a user by transferring heat generated by a thermoelectric operationincluding at least one of an exothermic operation and an endothermicoperation of a thermoelectric element to which power is applied, thethermal feedback being performed by a feedback device outputting thethermal feedback through a contact surface which contacts with theuser's body part, the method comprising: checking an operating powerapplied to the thermoelectric element for outputting the thermalfeedback, the operating power being determined according to a type andan intensity of the thermal feedback; applying a reduction power greaterthan the operating power during a predetermined time from an outputstart time point of the thermal feedback to shorten a time until atemperature of the contact surface reaches a target temperatureaccording to the type and the intensity of the thermal feedback; andapplying the operating power to the thermoelectric element after thepredetermined time elapses.
 2. The method of claim 1, wherein adirection of the reduction power is the same as a direction of theoperating power.
 3. The method of claim 1, wherein the applying thereduction power is applying the reduction power of a duty signal.
 4. Themethod of claim 1, wherein in the applying the reduction power, thetemperature of the contact surface reaches the target temperature morequickly when a first reduction voltage having a first voltage amplitudeis applied to the thermoelectric element than when a second reductionvoltage having a second voltage amplitude smaller than the first voltageamplitude is applied to the thermoelectric element.
 5. The method ofclaim 1, wherein in the applying the reduction power, the temperature ofthe contact surface reaches the target temperature more quickly when thereduction power is applied to the thermoelectric element during a firsttime interval from the output start time point than when the reductionpower is applied to the thermoelectric element during a second timeinterval smaller than the first time interval from the output start timepoint.
 6. The method of claim 1, wherein in the applying the reductionpower, the reduction power is applied such that the temperature of thecontact surface does not exceed the target temperature after thetemperature of the contact surface reaches the target temperature. 7.The method of claim 6, wherein in the applying the reduction power, avoltage amplitude of the reduction power is determined such that thetemperature of the contact surface does not reach the target temperatureduring the predetermined time.
 8. The method of claim 6, wherein in theapplying the reduction power, the predetermined time is determined suchthat the temperature of the contact surface does not reach the targettemperature during the predetermined time.
 9. The method of claim 1,wherein the applying the reduction power is applying the reduction powerso that a temperature change of the contact surface during thepredetermined time is greater than a temperature change of the contactsurface after terminating the application of the reduction power. 10.The method of claim 1, wherein: the applying the reduction power isperformed when the intensity of the thermal feedback is greater than orequal to a predetermined intensity.
 11. The method of claim 10, whereinthe method further comprises: obtaining the intensity of the thermalfeedback; generating the operating power based on the intensity of thethermal feedback; and determining whether to apply the reduction poweraccording to whether the intensity of the thermal feedback is greaterthan or equal to the predetermined intensity.
 12. The method of claim 1,wherein: the thermoelectric element comprises a thermoelectric couplearray including a plurality of individually controllable thermoelectriccouple groups, and in the applying the reduction power, applying thereduction power to at least one of the plurality of thermoelectriccouple groups.
 13. The method of claim 1, wherein the checking theoperating power includes: obtaining a thermal feedback data from anexternal device, and checking the operating power based on the thermalfeedback data.
 14. The method of claim 1, wherein: the method furthercomprises obtaining a thermal feedback data from an external device, thethermal feedback data including an information related to the outputstart time point of the thermal feedback, and the applying the reductionpower comprises determining a time point at which an application of thereduction power starts to a time point preceding the output start timepoint of the thermal feedback included in the thermal feedback data byconsidering a time reduction of the temperature of the contact surfacereaching the target temperature when the reduction power is applied, andapplying the reduction power at the determined time point at which theapplication of the reduction power starts.
 15. A method for providing athermal experience, the method comprising: reproducing a multimediacontent including a video data related to a video and a thermal feedbackdata related to a thermal feedback corresponding to a specific scene ofthe video; obtaining a thermoelectric operation start time point beingset as a time point preceding an output time point of the specific sceneby considering a delay time corresponding to a time from an initiationof a thermoelectric operation for the thermal feedback to a user'sexperience for the thermal feedback; and when a reproduction time pointof the multimedia content reaches the thermoelectric operation starttime point, transmitting a feedback initiation message to a feedbackdevice outputting the thermal feedback by transferring heat generated bythe thermoelectric operation of a thermoelectric element to the userthrough a contact surface which contacts with the user's body part, andwhen the reproduction time point of the multimedia content reaches theoutput time point of the specific scene, outputting the specific scenethrough a display such that the specific scene and the thermal feedbackare provided in conjunction with each other at the output time point ofthe specific scene to the user, wherein in the obtaining thethermoelectric operation start time point, when a reduction power forshortening a response time is applied to the thermoelectric element, thethermoelectric operation start time point is determined by considering areduction of the delay time according to a reduction of the responsetime, the response time being a time until a temperature of the contactsurface reaches a target temperature according to a type and anintensity of the thermal feedback.
 16. The method of claim 15, whereinthe delay time when the reduction power is applied to the thermoelectricelement is shorter than the delay time when the reduction power is notapplied to the thermoelectric element.
 17. The method of claim 15,wherein the thermoelectric operation start time point precedes thereproduction time point of the specific scene by the delay time.
 18. Afeedback device comprising: a heat output module including athermoelectric element, a power terminal and a contact surface, andoutputting a thermal feedback by transferring heat generated by athermoelectric operation including at least one of an exothermicoperation and an endothermic operation to a user through the contactsurface, wherein the thermoelectric element is configured to perform thethermoelectric operation, the power terminal is configured to supplypower for the thermoelectric operation to the thermoelectric element,and the contact surface is provided on one side surface of thethermoelectric element and contacts with the user's body part; and afeedback controller configured to: check an operating power applied tothe thermoelectric element for outputting the thermal feedback, theoperating power being determined according to a type and an intensity ofthe thermal feedback, and apply a reduction power greater than theoperating power during a predetermined time from an output start timepoint of the thermal feedback to shorten a time until a temperature ofthe contact surface reaches a target temperature according to the typeand the intensity of the thermal feedback.
 19. The device of claim 18,wherein: the device further comprises a communication module configuredto communicate with a content reproduction device reproducing amultimedia content, and the feedback controller is further configured toreceive an information, via the communication module, from the contentreproduction device, the information being related to the thermalfeedback.